This study set out to review and analyse aspects of antidepressant prescribing in children and adolescents in a section of the private health care sector of South Africa. The research was conducted in two phases, namely a literature review and an empirical investigation. The aim of the literature review was to provide background to the study by conceptualising antidepressants. The empirical review followed a retrospective, descriptive, observational design. The data employed in the study was obtained from the medicine claims database of a South African Pharmaceutical Benefit Management (PBM) company. The study population consisted of 3 611 children and adolescents receiving ≥1 antidepressants from 1 January 2010 to 31 December 2010. Basic descriptive statistics, such as frequency, prevalence, average, weighted average, standard deviation, weighted standard deviation, median, effect sizes, prescribed daily dosages and DU95% methodology were used to characterise the study sample, and were calculated using the Statistical Analysis System SAS® for Windows 9.3® program. The data were used to determine the prescribing patterns of antidepressants with regard to age, gender, geographic area, type of prescriber, the comparison of prescribed daily dosages vs. recommended daily dosages, and the prevalence of potential drug-drug interactions. Potential drug-drug interactions were identified and compiled by using various interaction compendia, whereas recommended daily dosages were identified by cross-referencing various dosage compendia. The study population consisted of 1 850 girls and 1 761 boys. The mean age of girls was 13.7 ± 3.9 years, vs. 12.3 ± 3.8 years for boys (d = 0.4). A total of 11 735 prescriptions containing 12 272 antidepressants were documented in 2010. Results of the study furthermore showed that the average number of prescriptions claimed per patient increased with age, from an average of 1.0 ± 0.28 among those up to the age of 2 years, to an average of 3.4 ± 3.21 among those 16 to 18 years of age. Prescribing with regard to age groups differed, rising gradually from birth and peaking at middle childhood for boys, whereas antidepressant use in girls increased from birth up to 6 years of age, reaching a plateau and increases again from age 13 and onward. Approximately 25% (n = 12 272) of antidepressants prescribed were either not indicated in children, or the dosages were deemed too high. More than 50% (n = 12 272) of antidepressants prescribed were in the Gauteng province. The SSRIs (selective serotonin re-uptake inhibitors) and the TCAs (tricyclic antidepressants) were the most prescribed antidepressants in both gender groups. The male-to-female ratio for the selective serotonin re-uptake inhibitors was 0.9, compared to 1.2 for the tricyclic antidepressants. The top three antidepressants prescribed were imipramine (21.8%), citalopram (15.3%) and escitalopram (14.7%, n = 12 272). Potential DDIs were observed on 284 (2.4%) (n = 11 743) prescriptions. The drug pairs with potential drug-drug interactions prescribed most, were imipramine with methylphenidate [43 cases (15.1%)] and valproic acid [38 cases (13.4%)], and followed by methylphenidate in combination with fluoxetine and sertraline [both documenting 32 cases (11.3%), respectively. The TCAs accounted for 182 (64.1%) cases of possible DDIs (drug-drug interactions), whereas combination therapy of SSRIs and TCAs accounted for 21.4% of potential DDIs. In conclusion, this study determined that there were a number of differences with regard to antidepressant prescribing in children and adolescents. Recommendations for future studies were made. / MPharm (Pharmacy Practice), North-West University, Potchefstroom Campus, 2014

This study set out to review and analyse aspects of antidepressant prescribing in children and adolescents in a section of the private health care sector of South Africa. The research was conducted in two phases, namely a literature review and an empirical investigation. The aim of the literature review was to provide background to the study by conceptualising antidepressants. The empirical review followed a retrospective, descriptive, observational design. The data employed in the study was obtained from the medicine claims database of a South African Pharmaceutical Benefit Management (PBM) company. The study population consisted of 3 611 children and adolescents receiving ≥1 antidepressants from 1 January 2010 to 31 December 2010. Basic descriptive statistics, such as frequency, prevalence, average, weighted average, standard deviation, weighted standard deviation, median, effect sizes, prescribed daily dosages and DU95% methodology were used to characterise the study sample, and were calculated using the Statistical Analysis System SAS® for Windows 9.3® program. The data were used to determine the prescribing patterns of antidepressants with regard to age, gender, geographic area, type of prescriber, the comparison of prescribed daily dosages vs. recommended daily dosages, and the prevalence of potential drug-drug interactions. Potential drug-drug interactions were identified and compiled by using various interaction compendia, whereas recommended daily dosages were identified by cross-referencing various dosage compendia. The study population consisted of 1 850 girls and 1 761 boys. The mean age of girls was 13.7 ± 3.9 years, vs. 12.3 ± 3.8 years for boys (d = 0.4). A total of 11 735 prescriptions containing 12 272 antidepressants were documented in 2010. Results of the study furthermore showed that the average number of prescriptions claimed per patient increased with age, from an average of 1.0 ± 0.28 among those up to the age of 2 years, to an average of 3.4 ± 3.21 among those 16 to 18 years of age. Prescribing with regard to age groups differed, rising gradually from birth and peaking at middle childhood for boys, whereas antidepressant use in girls increased from birth up to 6 years of age, reaching a plateau and increases again from age 13 and onward. Approximately 25% (n = 12 272) of antidepressants prescribed were either not indicated in children, or the dosages were deemed too high. More than 50% (n = 12 272) of antidepressants prescribed were in the Gauteng province. The SSRIs (selective serotonin re-uptake inhibitors) and the TCAs (tricyclic antidepressants) were the most prescribed antidepressants in both gender groups. The male-to-female ratio for the selective serotonin re-uptake inhibitors was 0.9, compared to 1.2 for the tricyclic antidepressants. The top three antidepressants prescribed were imipramine (21.8%), citalopram (15.3%) and escitalopram (14.7%, n = 12 272). Potential DDIs were observed on 284 (2.4%) (n = 11 743) prescriptions. The drug pairs with potential drug-drug interactions prescribed most, were imipramine with methylphenidate [43 cases (15.1%)] and valproic acid [38 cases (13.4%)], and followed by methylphenidate in combination with fluoxetine and sertraline [both documenting 32 cases (11.3%), respectively. The TCAs accounted for 182 (64.1%) cases of possible DDIs (drug-drug interactions), whereas combination therapy of SSRIs and TCAs accounted for 21.4% of potential DDIs. In conclusion, this study determined that there were a number of differences with regard to antidepressant prescribing in children and adolescents. Recommendations for future studies were made. / MPharm (Pharmacy Practice), North-West University, Potchefstroom Campus, 2014

Malaria is one the world’s most devastating diseases. Several classes of drugs are used to treat malaria. Artemisinin combination therapy is the first line treatment of uncomplicated malaria. The artemisinin derivative, artemisone in conjunction with the Pheroid® drug delivery system, is the focus of this thesis. The impact of the Pheroid® on the bioavailability of artemisone was evaluated in vervet monkeys. The resulting artemisone plasma levels were much lower (Cmax of 47 and 114 ng/mL for reference and Pheroid® test formulations respectively) than expected for the dosages administered (60 mg/kg). The Pheroid® improved the pharmacokinetic profile of artemisone in a clinically significant manner. The metabolism of artemisone was assessed in vitro by using human and monkey liver and intestinal microsomes, and recombinant CYP3A4 enzymes. The Pheroid® inhibits the microsomal metabolism of artemisone. In addition, there is a species difference in artemisone metabolism between man and monkey since the in vitro intrinsic clearance of the reference formulation with monkey liver microsomes is ~8 fold higher in the monkey liver microsomes compared to the human liver microsomes and the estimated in vivo hepatic clearance for the monkey is almost twofold higher than in humans. Artemisone has potent antimalarial activity. Its in vitro efficacy was approximately twofold higher than that of either artesunate or dihydroartemisinin when evaluated against P. falciparum W2, D6, 7G8, TM90-C2B, TM91-C235 and TM93-C1088 parasite strains. The Pheroid® drug delivery system did not improve or inhibit the in vitro efficacy of artemisone or DHA. Artemisone (reference and Pheroid® test formulations) and metabolite M1 abruptly arrested the growth of P. falciparum W2 parasites and induced the formation of dormant ring stages in a manner similar to that of DHA. Interaction of artemisone with the p-glycoprotein (p-gp) efflux transporter was investigated. Artemisone stimulates ATPase activity in a concentration-dependent manner, whereas the Pheroid® inhibited this p-gp ATPase activity. P-gp ATPase activity stimulation was fourfold greater in human than cynomolgus monkey MDR1 expressed insect cell membranes. Artemisone alone and artemisone entrapped in Pheroid® vesicles showed moderate apical to basolateral and high basolateral to apical permeability (Papp) across Caco-2 cells. The Papp efflux ratio of artemisone and artemisone entrapped in Pheroid® vesicles were both >5, and decreased to ~1 when the p-gp inhibitor, verapamil, was added. Therefore, artemisone is a substrate for mammalian p-gp. The cytotoxic properties of Pheroid® on Caco-2 cells were assessed and the pro-Pheroid® seems to be non-toxic at concentrations of 1.25%. Vervet monkey plasma caused antibody-mediated growth inhibition of P. falciparum. Heat inactivated or protein A treatment proved useful in the elimination of the growth-inhibitory activity of the drug-free plasma. Plasma samples containing artemisone could not be analysed by the ex-vivo bioassay method. The dual labelling ROS assay did not prove to be useful in the evaluation of ROS production by artemisone and the Pheroid® delivery system. In conclusion, entrapment of artemisone in the Pheroid® delivery system improves the pharmacokinetic properties of artemisone, but does not improve or inhibit its antimalarial efficacy in vitro. The Pheroid® inhibited both the microsomal metabolism of artemisone and P-gp ATPase activity and was shown to be non-toxic at clinically usable concentrations. / PhD (Pharmaceutics), North-West University, Potchefstroom Campus, 2014

Patients on anti-retroviral (ARV) drug treatment are sometimes simultaneously taking other prescribed drugs and/or over-the-counter drugs and/or herbal remedies. Pharmacokinetic drug-drug or herb-drug interactions can occur in these patients, which might be synergistic or antagonistic in nature leading to increased or decreased bioavailability of the ARV. Consequences of bioavailability changes may either be adverse effects due to increased plasma levels, or lack of pharmacological responses due to decreased plasma levels. The aim of this study is to determine if pharmacokinetic interactions exist between selected commercially available herbal products, namely Linctagon Forte®, Viral Choice® and Canova® and the ARV, indinavir, in terms of transport and metabolism in cell culture models. Bi-directional transport of indinavir was evaluated across Caco-2 cell monolayers in four experimental groups, namely indinavir alone (200 μM, negative control group), indinavir in combination with Linctagon Forte®, indinavir in combination with Viral Choice® and indinavir in combination with Canova® at three different concentrations. Verapamil (100 μM), a known P-gp inhibitor, was combined with indinavir in the positive control group. Samples obtained from the transport studies were analysed by means of a validated high performance liquid chromatography (HPLC) method. The apparent permeability coefficient (Papp) values were calculated from the transport results in both directions and the efflux ratio (ER) values were calculated from these Papp values. The metabolism of indinavir was determined in LS180 cells in the same groups as mentioned for the transport study but with ketoconazole (40 μM), a known CYP3A4 inhibitor, as the positive control group. Indinavir and its predominant metabolite (M6) were analysed in the metabolism samples by means of liquid chromatography linked to mass spectroscopy (LC/MS/MS) to determine the effect of the herbal products on the biotransformation of indinavir. The BL-AP transport of indinavir increased in a concentration dependent way in the presence of Linctagon Forte® and Viral Choice® when compared to that of indinavir alone (control group). Canova® only slightly affected the efflux of indinavir compared to that of the control group. Noticeable increases in the efflux ratio values of indinavir were found for Linctagon Forte® and Viral Choice®, whilst the effect of Canova® on the efflux ratio value was negligible. There was a pronounced inhibition of the metabolism of indinavir in LS180 cells over the entire concentration range for all the herbal products investigated in this study. These in vitro pharmacokinetic interactions indicate the selected herbal products may affect indinavir’s bioavailability, but the clinical significance needs to be confirmed with in vivo studies before final conclusions can be made. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

Malaria is one the world’s most devastating diseases. Several classes of drugs are used to treat malaria. Artemisinin combination therapy is the first line treatment of uncomplicated malaria. The artemisinin derivative, artemisone in conjunction with the Pheroid® drug delivery system, is the focus of this thesis. The impact of the Pheroid® on the bioavailability of artemisone was evaluated in vervet monkeys. The resulting artemisone plasma levels were much lower (Cmax of 47 and 114 ng/mL for reference and Pheroid® test formulations respectively) than expected for the dosages administered (60 mg/kg). The Pheroid® improved the pharmacokinetic profile of artemisone in a clinically significant manner. The metabolism of artemisone was assessed in vitro by using human and monkey liver and intestinal microsomes, and recombinant CYP3A4 enzymes. The Pheroid® inhibits the microsomal metabolism of artemisone. In addition, there is a species difference in artemisone metabolism between man and monkey since the in vitro intrinsic clearance of the reference formulation with monkey liver microsomes is ~8 fold higher in the monkey liver microsomes compared to the human liver microsomes and the estimated in vivo hepatic clearance for the monkey is almost twofold higher than in humans. Artemisone has potent antimalarial activity. Its in vitro efficacy was approximately twofold higher than that of either artesunate or dihydroartemisinin when evaluated against P. falciparum W2, D6, 7G8, TM90-C2B, TM91-C235 and TM93-C1088 parasite strains. The Pheroid® drug delivery system did not improve or inhibit the in vitro efficacy of artemisone or DHA. Artemisone (reference and Pheroid® test formulations) and metabolite M1 abruptly arrested the growth of P. falciparum W2 parasites and induced the formation of dormant ring stages in a manner similar to that of DHA. Interaction of artemisone with the p-glycoprotein (p-gp) efflux transporter was investigated. Artemisone stimulates ATPase activity in a concentration-dependent manner, whereas the Pheroid® inhibited this p-gp ATPase activity. P-gp ATPase activity stimulation was fourfold greater in human than cynomolgus monkey MDR1 expressed insect cell membranes. Artemisone alone and artemisone entrapped in Pheroid® vesicles showed moderate apical to basolateral and high basolateral to apical permeability (Papp) across Caco-2 cells. The Papp efflux ratio of artemisone and artemisone entrapped in Pheroid® vesicles were both >5, and decreased to ~1 when the p-gp inhibitor, verapamil, was added. Therefore, artemisone is a substrate for mammalian p-gp. The cytotoxic properties of Pheroid® on Caco-2 cells were assessed and the pro-Pheroid® seems to be non-toxic at concentrations of 1.25%. Vervet monkey plasma caused antibody-mediated growth inhibition of P. falciparum. Heat inactivated or protein A treatment proved useful in the elimination of the growth-inhibitory activity of the drug-free plasma. Plasma samples containing artemisone could not be analysed by the ex-vivo bioassay method. The dual labelling ROS assay did not prove to be useful in the evaluation of ROS production by artemisone and the Pheroid® delivery system. In conclusion, entrapment of artemisone in the Pheroid® delivery system improves the pharmacokinetic properties of artemisone, but does not improve or inhibit its antimalarial efficacy in vitro. The Pheroid® inhibited both the microsomal metabolism of artemisone and P-gp ATPase activity and was shown to be non-toxic at clinically usable concentrations. / PhD (Pharmaceutics), North-West University, Potchefstroom Campus, 2014

Patients on anti-retroviral (ARV) drug treatment are sometimes simultaneously taking other prescribed drugs and/or over-the-counter drugs and/or herbal remedies. Pharmacokinetic drug-drug or herb-drug interactions can occur in these patients, which might be synergistic or antagonistic in nature leading to increased or decreased bioavailability of the ARV. Consequences of bioavailability changes may either be adverse effects due to increased plasma levels, or lack of pharmacological responses due to decreased plasma levels. The aim of this study is to determine if pharmacokinetic interactions exist between selected commercially available herbal products, namely Linctagon Forte®, Viral Choice® and Canova® and the ARV, indinavir, in terms of transport and metabolism in cell culture models. Bi-directional transport of indinavir was evaluated across Caco-2 cell monolayers in four experimental groups, namely indinavir alone (200 μM, negative control group), indinavir in combination with Linctagon Forte®, indinavir in combination with Viral Choice® and indinavir in combination with Canova® at three different concentrations. Verapamil (100 μM), a known P-gp inhibitor, was combined with indinavir in the positive control group. Samples obtained from the transport studies were analysed by means of a validated high performance liquid chromatography (HPLC) method. The apparent permeability coefficient (Papp) values were calculated from the transport results in both directions and the efflux ratio (ER) values were calculated from these Papp values. The metabolism of indinavir was determined in LS180 cells in the same groups as mentioned for the transport study but with ketoconazole (40 μM), a known CYP3A4 inhibitor, as the positive control group. Indinavir and its predominant metabolite (M6) were analysed in the metabolism samples by means of liquid chromatography linked to mass spectroscopy (LC/MS/MS) to determine the effect of the herbal products on the biotransformation of indinavir. The BL-AP transport of indinavir increased in a concentration dependent way in the presence of Linctagon Forte® and Viral Choice® when compared to that of indinavir alone (control group). Canova® only slightly affected the efflux of indinavir compared to that of the control group. Noticeable increases in the efflux ratio values of indinavir were found for Linctagon Forte® and Viral Choice®, whilst the effect of Canova® on the efflux ratio value was negligible. There was a pronounced inhibition of the metabolism of indinavir in LS180 cells over the entire concentration range for all the herbal products investigated in this study. These in vitro pharmacokinetic interactions indicate the selected herbal products may affect indinavir’s bioavailability, but the clinical significance needs to be confirmed with in vivo studies before final conclusions can be made. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

Antiretroviral drugs are successful in controlling HIV/AIDS and reducing disease progression. Antiretroviral regimens are stopped in up to 25% of all patients during their initial treatment therapy as a result of adverse drug effects, failing treatment and nonadherence within the initial eight months of treatment (Sharma et al., 2007: 235). A pharmacovigilance surveillance system makes it possible for physicians, pharmacists and other healthcare providers to report suspected ADRs. The purpose of this system is to operate as a guide in identification of new ADRs and predisposing risk factors to known ADRs. The objective of this study was to assess the prevalence and documentation of adverse drug reactions (ADR) in the private and public antiretroviral clinics in Maseru district, with special reference to zidovudine (AZT) and tenofovir (TDF) - based regimens. The empirical investigation was divided into two phases. The first phase was a cross-sectional quantitative retrospective drug utilisation review study which focused on the occurrence of adverse drug reactions in patients taking zidovudine (AZT) and tenofovir (TDF). The second phase, a survey in a form of questionnaires for the health professionals. Drug utilisation review: The sample size of patients was 300. Of the 44 patients who experience ADRs, 72.73% (n = 32) were female and 27.27% (n = 12) were male. A greater number of patients who experienced ADRs were females with 43.18% (n = 19) presenting with skin rash, 27.27% (n = 12) with nausea/vomiting, and 2.27% (n = 1) with diarrhoea. In male patients, 2.27% (n = 1) had peripheral neuropathy, 18.18% (n = 8) skin rash, 2.27% (n = 1) Fanconi syndrome, 2.27% (n = 1) nausea/vomiting, and 2.27% (n = 1) diarrhoea. Patients whose ART regimen changed due to ADRs were five. 60% (n = 3) of the patients were females and 40% (n = 2) were males. There was an estimated increase of 0.0025 cell/mm³, 0.0026 cell/mm³, 0.0024 cell/mm³, 0.0025 cell/mm³, and of 0.0019 cell/mm³ in CD4 cell count per day according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. An estimated increase of 0.00021 g/dL, 0.00022 g/dL, 0.00018 g/dL, 0.00022 g/dL, and of 0.00020 g/dL in Hb profile per day occurred according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. There was an estimated increase of 0.000062%, 0.000046%, 0.000068%, 0.000062%, and of 0.00017% in neutrophil count according to sex, age group, weight group, initial ART regimen, and ADRs per day, respectively. There was an estimated increase of 0.000044 IU/L, 0.000043 IU/L, 0.000046 IU/L, and of 0.000028 IU/L in ALT according to sex, age group, weight group, and initial ART regimen per day, respectively. An estimated decrease of 0.000013 IU/L in ALT according to ADRs per day also occurred. There was an estimated decrease of 0.00038 μmol/L, 0.00039 μmol/L, 0.00040 μmol/L, 0.00040 μmol/L, and of 0.00028 μmol/L in serum creatinine per day according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. There was an estimated decline of 0.00023 mmol/L, 0.00022 mmol/L, 0.00023 mmol/L, 0.00024 mmol/L, and of 0.00015 mmol/L per day in urea according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. Health professional’s questionnaire: 49 health professionals responded to the questionnaire. 100% (n= 49) of the participants showed that they did not use the yellow card scheme to report ADRs. 34.65% (n = 17) use the individual case safety reports. 57.14% (n = 28) used the structured databases to report ADRs. 85.71% (n = 42) documented in the patient bukana, and 6.12% (n = 3) used the HIV/AIDS ART card to document ADRs occurrence. 91.84% (n = 45) of the health professionals never filled the ADR reporting form in their working environment. In conclusion, adverse drug reactions occurring in a hospital or healthcare facility should be recorded and reported by the medical practitioners, nurses, pharmacists, and the pharmacy technicians. Therefore, it is important to assess the continuous evaluation of the benefits and harm of medicines which will help in achieving the ultimate goal of making safer and more effective treatment available for patients. As well as to help the health professionals to participate in the very important process of continuous surveillance of safety and efficacy of pharmaceutical products used in clinical practice. / MPham (Pharmacy Practice), North-West University, Potchefstroom Campus, 2014

Antiretroviral drugs are successful in controlling HIV/AIDS and reducing disease progression. Antiretroviral regimens are stopped in up to 25% of all patients during their initial treatment therapy as a result of adverse drug effects, failing treatment and nonadherence within the initial eight months of treatment (Sharma et al., 2007: 235). A pharmacovigilance surveillance system makes it possible for physicians, pharmacists and other healthcare providers to report suspected ADRs. The purpose of this system is to operate as a guide in identification of new ADRs and predisposing risk factors to known ADRs. The objective of this study was to assess the prevalence and documentation of adverse drug reactions (ADR) in the private and public antiretroviral clinics in Maseru district, with special reference to zidovudine (AZT) and tenofovir (TDF) - based regimens. The empirical investigation was divided into two phases. The first phase was a cross-sectional quantitative retrospective drug utilisation review study which focused on the occurrence of adverse drug reactions in patients taking zidovudine (AZT) and tenofovir (TDF). The second phase, a survey in a form of questionnaires for the health professionals. Drug utilisation review: The sample size of patients was 300. Of the 44 patients who experience ADRs, 72.73% (n = 32) were female and 27.27% (n = 12) were male. A greater number of patients who experienced ADRs were females with 43.18% (n = 19) presenting with skin rash, 27.27% (n = 12) with nausea/vomiting, and 2.27% (n = 1) with diarrhoea. In male patients, 2.27% (n = 1) had peripheral neuropathy, 18.18% (n = 8) skin rash, 2.27% (n = 1) Fanconi syndrome, 2.27% (n = 1) nausea/vomiting, and 2.27% (n = 1) diarrhoea. Patients whose ART regimen changed due to ADRs were five. 60% (n = 3) of the patients were females and 40% (n = 2) were males. There was an estimated increase of 0.0025 cell/mm³, 0.0026 cell/mm³, 0.0024 cell/mm³, 0.0025 cell/mm³, and of 0.0019 cell/mm³ in CD4 cell count per day according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. An estimated increase of 0.00021 g/dL, 0.00022 g/dL, 0.00018 g/dL, 0.00022 g/dL, and of 0.00020 g/dL in Hb profile per day occurred according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. There was an estimated increase of 0.000062%, 0.000046%, 0.000068%, 0.000062%, and of 0.00017% in neutrophil count according to sex, age group, weight group, initial ART regimen, and ADRs per day, respectively. There was an estimated increase of 0.000044 IU/L, 0.000043 IU/L, 0.000046 IU/L, and of 0.000028 IU/L in ALT according to sex, age group, weight group, and initial ART regimen per day, respectively. An estimated decrease of 0.000013 IU/L in ALT according to ADRs per day also occurred. There was an estimated decrease of 0.00038 μmol/L, 0.00039 μmol/L, 0.00040 μmol/L, 0.00040 μmol/L, and of 0.00028 μmol/L in serum creatinine per day according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. There was an estimated decline of 0.00023 mmol/L, 0.00022 mmol/L, 0.00023 mmol/L, 0.00024 mmol/L, and of 0.00015 mmol/L per day in urea according to sex, age group, weight group, initial ART regimen, and ADRs, respectively. Health professional’s questionnaire: 49 health professionals responded to the questionnaire. 100% (n= 49) of the participants showed that they did not use the yellow card scheme to report ADRs. 34.65% (n = 17) use the individual case safety reports. 57.14% (n = 28) used the structured databases to report ADRs. 85.71% (n = 42) documented in the patient bukana, and 6.12% (n = 3) used the HIV/AIDS ART card to document ADRs occurrence. 91.84% (n = 45) of the health professionals never filled the ADR reporting form in their working environment. In conclusion, adverse drug reactions occurring in a hospital or healthcare facility should be recorded and reported by the medical practitioners, nurses, pharmacists, and the pharmacy technicians. Therefore, it is important to assess the continuous evaluation of the benefits and harm of medicines which will help in achieving the ultimate goal of making safer and more effective treatment available for patients. As well as to help the health professionals to participate in the very important process of continuous surveillance of safety and efficacy of pharmaceutical products used in clinical practice. / MPham (Pharmacy Practice), North-West University, Potchefstroom Campus, 2014

Background: Warfarin is an anticoagulant that is used for the prophylactic and therapeutic treatment for a wide range of thrombo-embolic disorders. The prescribing and monitoring of warfarin therapy is challenging due to the fact that warfarin exhibits numerous interactions with other drugs and a variety of factors that influence the dosing of warfarin. Objective: The general objective of this study was to investigate the prevalence of drugs prescribed with warfarin that may have a potential drug-drug interaction (DDI) with warfarin. Methods: This was a cross-sectional, observational or qualitative study that was conducted on medicine claims data of a pharmaceutical benefit management company for patients receiving warfarin therapy for a six year period, ranging from 1 January 2005 to 31 December 2010. Drug products that were co-prescribed with warfarin were also identified from the medicine claims database. The total number of prescriptions for all drug products during the study period were analysed and compared to the warfarin dataset. This was done by means of the SAS 9.1® computer package (SAS Institute, 2004). The total number of prescriptions and medicine items claimed from the database during the study period were respectively 49 523 818 and 118 305 941. Potential DDls between warfarin and coprescribed drugs were identified and classified according to a clinically significant rating. The clinically significance ratings of potential DDls are described in three degrees of severity, identified as major, moderate and minor (Tatro, 2011 :xiv). Results: The database consisted of 427 238 warfarin prescriptions and 427 744 warfarin medicine items, which represented 0.9% of the total number of prescriptions and 0.4% of total number of medicine items. The total number of patients who claimed warfarin prescriptions through the database represented 0.9% (n=68 575) of the total number of patients who claimed prescriptions in the total database (2005-2010). General practitioners prescribed the highest frequency of warfarin medicine items, representing 58.3% (n=249 202) of the total number prescribed. The age group that claimed the highest frequency of warfarin prescriptions (n=327 592, 76.6%) and the highest frequency of warfarin medicine items (n=327 984, 76.7%) was age group 4 (consisting of patients 59 years and older). The distribution between females and males regarding warfarin prescriptions claimed (n=205 999, 48.2%; n=221 117, 51.8%) and warfarin medicine items claimed (n=206 232, 48.2%; n=221 390, 51.8%) were almost equal. General practitioners prescribed the highest average PDD (7.01 mg ± 9.86 mg) of warfarin medicine items. Paediatric cardiologists prescribed the lowest average PDD (4.61 mg ± 1.29 mg) of warfarin medicine items. A d-value of 0.1 indicates that there is no practical difference of the average PDD between general practitioners and paediatric cardiologists. The average PDD of warfarin medicine items between females (6.60 mg ± 9.06 mg) and males (6.74 mg± 8.41 mg) was almost equal. The age group who was prescribed the highest average PDD was age group 2 (consisting of patients 20 years to 39 years old) (7.42 mg± 7.42 mg). Age group 4 (consisting of patients 59 years and older) (6.50 mg± 8.90 mg) was prescribed the lowest average PDD of warfarin medicine items. A d-value of 0.1 indicates that there is no practical difference of the average PDDs of warfarin medicine items between these two age groups. The results revealed that drugs with a significance rating (SR) of 1 (n=155 066, 43.3%), 2 (n=30128, 8.4%), 4 (n=137144, 38.3%), and 5 (n=36144, 10.1%) were co-prescribed with warfarin in the six year study period. The five drugs that was co-prescribed with warfarin most frequently was aspirin (n=48 903, 13.6%), thyroxine (n=33 954, 9.5%), amiodarone (n=25 056, 7.0%), simvastatin (n=19 070, 5.3%) and celecoxib (n=10 794, 3.0%). These five drugs have a SR of 1. Conclusions: This study showed that the top five drugs most frequently prescribed with warfarin are aspirin, thyroxine, amiodarone, simvastatin and celecoxib. These drugs can potentially interact with warfarin. The potential interactions of these drugs are rated with a significance rating of 1. This concludes that drugs that can potentially cause life threatening effects and permanent damage are commonly co-prescribed with warfarin. Clinical data concerning the INR or PT must be obtained in order to evaluate whether or not warfarin therapy is changed when a potentially interacting drug is co-prescribed. The age of the patients as well as the duration of warfarin treatment should also be obtained in order to assess whether warfarin treatment is changed with the progression of age. / MPharm (Pharmacy Practice), North-West University, Potchefstroom Campus, 2013

Background: Warfarin is an anticoagulant that is used for the prophylactic and therapeutic treatment for a wide range of thrombo-embolic disorders. The prescribing and monitoring of warfarin therapy is challenging due to the fact that warfarin exhibits numerous interactions with other drugs and a variety of factors that influence the dosing of warfarin. Objective: The general objective of this study was to investigate the prevalence of drugs prescribed with warfarin that may have a potential drug-drug interaction (DDI) with warfarin. Methods: This was a cross-sectional, observational or qualitative study that was conducted on medicine claims data of a pharmaceutical benefit management company for patients receiving warfarin therapy for a six year period, ranging from 1 January 2005 to 31 December 2010. Drug products that were co-prescribed with warfarin were also identified from the medicine claims database. The total number of prescriptions for all drug products during the study period were analysed and compared to the warfarin dataset. This was done by means of the SAS 9.1® computer package (SAS Institute, 2004). The total number of prescriptions and medicine items claimed from the database during the study period were respectively 49 523 818 and 118 305 941. Potential DDls between warfarin and coprescribed drugs were identified and classified according to a clinically significant rating. The clinically significance ratings of potential DDls are described in three degrees of severity, identified as major, moderate and minor (Tatro, 2011 :xiv). Results: The database consisted of 427 238 warfarin prescriptions and 427 744 warfarin medicine items, which represented 0.9% of the total number of prescriptions and 0.4% of total number of medicine items. The total number of patients who claimed warfarin prescriptions through the database represented 0.9% (n=68 575) of the total number of patients who claimed prescriptions in the total database (2005-2010). General practitioners prescribed the highest frequency of warfarin medicine items, representing 58.3% (n=249 202) of the total number prescribed. The age group that claimed the highest frequency of warfarin prescriptions (n=327 592, 76.6%) and the highest frequency of warfarin medicine items (n=327 984, 76.7%) was age group 4 (consisting of patients 59 years and older). The distribution between females and males regarding warfarin prescriptions claimed (n=205 999, 48.2%; n=221 117, 51.8%) and warfarin medicine items claimed (n=206 232, 48.2%; n=221 390, 51.8%) were almost equal. General practitioners prescribed the highest average PDD (7.01 mg ± 9.86 mg) of warfarin medicine items. Paediatric cardiologists prescribed the lowest average PDD (4.61 mg ± 1.29 mg) of warfarin medicine items. A d-value of 0.1 indicates that there is no practical difference of the average PDD between general practitioners and paediatric cardiologists. The average PDD of warfarin medicine items between females (6.60 mg ± 9.06 mg) and males (6.74 mg± 8.41 mg) was almost equal. The age group who was prescribed the highest average PDD was age group 2 (consisting of patients 20 years to 39 years old) (7.42 mg± 7.42 mg). Age group 4 (consisting of patients 59 years and older) (6.50 mg± 8.90 mg) was prescribed the lowest average PDD of warfarin medicine items. A d-value of 0.1 indicates that there is no practical difference of the average PDDs of warfarin medicine items between these two age groups. The results revealed that drugs with a significance rating (SR) of 1 (n=155 066, 43.3%), 2 (n=30128, 8.4%), 4 (n=137144, 38.3%), and 5 (n=36144, 10.1%) were co-prescribed with warfarin in the six year study period. The five drugs that was co-prescribed with warfarin most frequently was aspirin (n=48 903, 13.6%), thyroxine (n=33 954, 9.5%), amiodarone (n=25 056, 7.0%), simvastatin (n=19 070, 5.3%) and celecoxib (n=10 794, 3.0%). These five drugs have a SR of 1. Conclusions: This study showed that the top five drugs most frequently prescribed with warfarin are aspirin, thyroxine, amiodarone, simvastatin and celecoxib. These drugs can potentially interact with warfarin. The potential interactions of these drugs are rated with a significance rating of 1. This concludes that drugs that can potentially cause life threatening effects and permanent damage are commonly co-prescribed with warfarin. Clinical data concerning the INR or PT must be obtained in order to evaluate whether or not warfarin therapy is changed when a potentially interacting drug is co-prescribed. The age of the patients as well as the duration of warfarin treatment should also be obtained in order to assess whether warfarin treatment is changed with the progression of age. / MPharm (Pharmacy Practice), North-West University, Potchefstroom Campus, 2013