Effectiveness of a structured stimulated spontaneous safety monitoring of medicines reporting program in strengthening pharmacovigilance system in Tanzania.

Under-reporting of adverse drug events (ADEs) is a challenge facing developing countries including Tanzania. Given the high magnitude of under-reporting, it was necessary to develop and assess the effectiveness of a 'structured stimulated spontaneous safety monitoring' (SSSSM) reporting program of ADEs which aimed at strengthening pharmacovigilance system in Tanzania. A quasi-experimental design and data mining technique were used to assess the effect of intervention after the introduction of program in seven tertiary hospitals. ADEs reports were collected from a single group and compared for 18 months before (July 2017 to December, 2018) and after the program (January 2019 to June 2020). Out of 16,557 ADEs reports, 98.6% (16,332) were reported after intervention and 0.1% (23) death related to adverse drug reactions (ADRs) were reported. Reports increased from 20 to 11,637 after intervention in Dar es salaam, 49 to 316 in Kilimanjaro and 17 to 77 in Mbeya. The population-based reporting ratio per 1,000,000 inhabitants increased from 2 reports per million inhabitants in 2018 to 85 reports in 2019. The SSSSM program can increase the reporting rate of ADEs and was useful in detecting signals from all types of medicines. This was first effective developed spontaneous program to monitor medicine safety in Tanzania.

Awareness and Reporting of Antiretroviral Adverse Events Among Clients and Health-Care Providers at a Referral Hospital in Moshi, Northern Tanzania: A Cross-Sectional Study.

BACKGROUND: Pharmacovigilance is a means of ensuring drug safety, and thus it ensures that the risks associated with medication adminstration and consumption do not outweigh the benefits. Antiretroviral therapy (ART) for HIV care and treatment has reduced mortality and morbidity, but adverse drug reactions (ADRs), which can lead to treatment failure, remain a concern. In 2015 in Tanzania, 688,800 adults were taking ART. All health-care providers are required to report all suspected ADRs seen or reported by their patients using yellow forms available at all care and treatment centres in Tanzania. However, the actual practice of reporting is not taking place. This study aimed to explore the patients' knowledge and HIV/AIDS health-care providers' reporting of ART adverse events at Kilimanjaro Christian Medical Centre (KCMC). METHODS: A cross-sectional study using a semi-structured questionnaire was conducted between June and July 2016 within HIV, dermatology, and infectious disease clinics at KCMC. All health-care providers providing HIV services within these clinics completed a questionnaire. Means and standard deviations were used to summarise the numerical data with normal distributions (age of patients), while numerical data that were not normally distributed (duration on ART) were summarised using medians and ranges. Frequencies and percentages were used to summarise categorical variables. RESULTS: All 63 health-care providers agreed that ADR reporting was necessary. Forty-six (73%) were aware of the national ADR reporting system, but only 32 (50.8%) reported having received training on pharmacovigilance. Only 4 (6.3%) of all health-care providers reported always filling the ADR report forms; 27 (42.9%) rarely filled the forms, and 32 (50.8%) reported having never filled an ADR reporting form. Training on pharmacovigilance had a positive influence on ADR reporting. Lack of motivation, uncertainty about reporting procedures, lack of time, unavailability of reporting forms, and ignorance were the major factors affecting reporting among health-care providers. CONCLUSION: The majority of health-care providers were aware of the need and importance of ADR reporting and the national pharmacovigilance system. However, ART adverse events are underreported. More effort is needed to strengthen the continuous reporting of ADRs by providing continuous education to health-care providers; this will lead to their active participation in pharmacovigilance.

Evaluation of Prescriptions Dispensed in the Outpatient Pharmacies of a University Teaching Hospital in Moshi, Kilimanjaro Region, Tanzania: A Cross-Sectional Study.

BACKGROUND: Prescriptions written in daily medical practice are associated with increasing numbers of prescription writing errors. Both omission and commission errors are encountered and caused by prescribers of different cadres. Prescribing errors are associated with adverse drug events (ADEs), which are harmful to patients. This study aimed to determine the common prescription errors, the categories of prescribers who commit prescription errors, and the most prescribed drugs in the outpatient pharmacies in general practice at Kilimanjaro Christian Medical Centre (KCMC). METHODS: A prospective cross-sectional descriptive study was conducted at KCMC, a referral and teaching university hospital. All prescription dispensed on 2 June 2017 from the hospital's 2 outpatient pharmacies were reviewed, and our analysis determined the different types of prescription errors. A form designed by the authors was used to collect data from the prescription forms. RESULTS: A total of 242 prescriptions were studied, and the most common omission errors were missing patients' weight (n=231, 95.5%), missing patients' address (n=213, 88.0%), missing drug dosage (n=159, 67.1%), and commission errors were due to wrong drug strength (n=10, 2.0%). Intern doctors were leading in writing prescriptions with errors (n=352, 25.6%), followed by residents (n=199, 14.5%), registrar doctors (n=167, 12.1%), and specialists (n=45, 3.3%). The most commonly prescribed drugs were antibiotics (n=120, 17.3%), antihypertensives (n=81, 11.7%), and analgesics (n=86, 12.4%). CONCLUSION: There were significant prescription errors at the study site, hence an intervention is needed to improve skills of prescribers. Educational interventions can substantially contribute to minimising such errors. Initaiting programmes and short courses on prescription writing before medical internship at the health facility might also be helpful.

Nevirapine concentrations in saliva measured by thin layer chromatography and self-reported adherence in patients on antiretroviral therapy at Kilimanjaro Christian Medical Centre, Tanzania.

BACKGROUND: Thin layer chromatography (TLC) can be used to perform therapeutic drug monitoring in resource-limited settings, where more expensive analytical methods, such as high-performance liquid chromatography or liquid chromatography-mass spectrometry, are not feasible. OBJECTIVES: The aim of this cross-sectional study was to compare saliva concentrations of nevirapine (NVP) with self-reported adherence in patients on NVP-containing antiretroviral treatment at Kilimanjaro Christian Medical Centre, Moshi, Tanzania. METHODS: HIV-infected patients using a combination of zidovudine + lamivudine + NVP, or stavudine + lamivudine + NVP, for more than 4 weeks were included. Saliva samples were collected using dental cotton rolls impregnated with citric acid (20 mg). Saliva NVP concentrations were analyzed using TLC. Adherence to ARV medication was assessed by self-reporting using the Morisky scale. RESULTS: Of the 91 study participants, 79 (86.8%) had therapeutic saliva NVP concentrations (ie, >1.75 mg/L) and 12 (13.2%) had subtherapeutic concentrations. Self-reported adherence among the study participants was high in 62 participants (68.1%), moderate in 24 (26.4%), and low in 5 (5.5%). Fifty-seven (91.9%) of the study participants with high self-reported adherence had therapeutic saliva NVP concentrations. Of the 5 participants with low self-reported adherence, 3 had therapeutic NVP concentrations. CONCLUSIONS: A high proportion of patients had therapeutic NVP saliva concentrations as measured by TLC, which showed a good agreement with self-reported adherence.

Effect of 7 days of phenytoin on the pharmacokinetics of and the development of resistance to single-dose nevirapine for perinatal HIV prevention: a randomized pilot trial.

OBJECTIVES: To confirm whether 7 days of phenytoin, an enzyme inducer, would decrease the elimination half-life of single-dose nevirapine and to investigate its effect on the development of nevirapine resistance in pregnant, HIV-infected women. METHODS: In a pharmacokinetic pilot trial (NCT01187719), HIV-infected, antiretroviral (ARV)-naive pregnant women ≥18 years old from Zambia and Tanzania and with CD4 cell counts >350 cells/mm(3) were randomized 1 : 1 to a control (zidovudine pre-delivery, single-dose nevirapine/zidovudine/lamivudine at delivery and zidovudine/lamivudine for 7 days post-delivery) or an intervention (control plus 184 mg of phenytoin once daily for 7 days post-delivery) group. Primary endpoints were the pharmacokinetics of and resistance to nevirapine. RESULTS: Thirty-five and 37 women were allocated to the control and intervention groups, with median (IQR) ages of 27 (23-31) and 27 (23-33) years, respectively. Twenty-three and 23 women had detectable nevirapine levels at delivery and subsequent samples in the control and the intervention groups, respectively. Geometric mean (GM) (95% CI) plasma levels of nevirapine at delivery were 1.02 (0.58-1.78) mg/L and 1.14 (0.70-1.86) mg/L in the control and intervention groups, respectively (P = 0.76). One week after delivery, 0/23 (0%) and 15/22 (68%) control and intervention mothers, respectively, had undetectable levels of nevirapine (<0.05 mg/L; P<0.001). One week later, the figures were 10/21 (48%) and 18/19 (95%) mothers, respectively (P = 0.002). The GM (95% CI) half-life of nevirapine was 63.2 (52.8-75.7) versus 25.5 (21.6-30.1) h in the control group versus the intervention group (P < 0.001). New nevirapine mutations were found in 0/20 (0%) intervention-group mothers versus 1/21 (5%) control-group mothers. Overall, there was no difference in adverse events reported between the control and intervention arms (P > 0.28). CONCLUSIONS: Adding 7 days of an enzyme inducer to single-dose nevirapine to prevent mother-to-child transmission of HIV significantly reduced subtherapeutic nevirapine levels by shortening the half-life of nevirapine. As prolonged subtherapeutic nevirapine dosage leads to the emergence of resistance, single-dose nevirapine could be used with phenytoin as an alternative if other ARVs were unavailable.

Intrapartum single-dose carbamazepine reduces nevirapine levels faster and may decrease resistance after a single dose of nevirapine for perinatal HIV prevention.

BACKGROUND: World Health Organization guidelines recommend zidovudine + lamivudine for 7 days from labor onset in HIV-infected women receiving single-dose nevirapine (sdNVP) to cover prolonged subtherapeutic nevirapine concentrations. Although effective, this is complicated and does not eliminate resistance; alternative strategies could add benefit. METHODS: Antiretroviral-naive HIV-infected pregnant women aged 18-40 years, with CD4 >200 cells per cubic millimeter, able to regularly attend the antenatal clinics in Moshi, Tanzania, were enrolled 1:1 by alternate allocation to receive 200 mg sdNVP alone or in combination with open-label 400-mg single-dose carbamazepine (sdNVP/CBZ) at delivery (ClinicalTrials.gov NCT00294892). The coprimary outcomes were nevirapine plasma concentrations 1 week and nevirapine resistance mutations 6 weeks postpartum. Analyses were based on those still eligible at delivery. RESULTS: Ninety-seven women were assigned to sdNVP and 95 to sdNVP/CBZ during pregnancy, of whom 75 sdNVP and 83 sdNVP/CBZ were still eligible at delivery at study sites. The median (interquartile range) nevirapine plasma concentration was 1.55 (0.88-1.84) mg/L in sdNVP (n = 61) and 1.40 (0.93-1.97) mg/L in sdNVP/CBZ (n = 72) at delivery (P = 0.91), but 1 week later was significantly lower in sdNVP/CBZ [n = 63; 0.09 (0.05-0.20) mg/L] than in sdNVP [n = 52; 0.20 (0.09-0.31) mg/L; rank-sum: P = 0.004] (geometric mean ratio: 0.64, 95% confidence interval: 0.43 to 0.96; P = 0.03). Six weeks postpartum, nevirapine mutations were observed in 11 of 52 (21%) in sdNVP and 6 of 55 (11%) in sdNVP/CBZ (odds ratio = 0.46, 95% confidence interval: 0.16 to 1.34; P = 0.15). CONCLUSIONS: Addition of single-dose carbamazepine to sdNVP at labor onset in HIV-infected, pregnant women did not affect nevirapine plasma concentration at delivery, but significantly reduced it 1 week postpartum, with a trend toward fewer nevirapine resistance mutations.

Therapeutic drug monitoring of nevirapine in resource-limited settings.

BACKGROUND: We developed a simple and inexpensive thin-layer chromatography (TLC) assay for semiquantitative detection of saliva concentrations of nevirapine in resource-limited settings. The method was validated in an African target population. METHODS: Paired plasma and saliva nevirapine concentrations were assayed by high-performance liquid chromatography (HPLC); saliva concentrations of nevirapine were also assayed by TLC. The rate of false-positive results was the proportion of subtherapeutic nevirapine saliva and plasma concentrations determined by HPLC that were judged to be therapeutic in saliva specimens by TLC. The rate of false-negative results was the proportion of therapeutic nevirapine saliva and plasma concentrations determined by HPLC that were judged to be subtherapeutic in saliva specimens by TLC. The extent of agreement in TLC readings between 5 technicians and 2 batches of TLC sheets was evaluated. RESULTS: Twenty-five (9%) of 286 African adults had a subtherapeutic plasma nevirapine concentration. The median ratio of nevirapine concentrations in saliva to those in plasma was 0.51:1. The rate of false-positive results for TLC was 0% (0 of 23 specimens) when TLC results were compared with HPLC results for saliva specimens and 8% (2 of 25 specimens) when TLC results were compared with HPLC results for plasma specimens. The rate of false-negative results for TLC was 1% (3 of 263 specimens) when TLC results were compared with HPLC results for saliva specimens and 1% (3 of 261 specimens) when TLC results were compared with HPLC results for plasma specimens. The extent of agreement of TLC results was substantial for the 5 technicians (Fleiss's kappa = 0.77) and for the 2 batches of sheets (Cohen's kappa = 0.80). CONCLUSIONS: The TLC assay was found to be sensitive, specific, and robust in the detection of subtherapeutic nevirapine concentrations in saliva specimens obtained from African HIV-infected adults. It is an attractive alternative to HPLC for therapeutic drug monitoring of nevirapine in resource-limited settings.

Generic and branded drugs for the treatment of people living with HIV/AIDS.

HIV/AIDS care has benefited tremendously from the availability of antiretroviral (ARV) drugs, both branded and generic. Drug discovery and innovation is the result of direct investment in the development of branded medications, a crucial process for future improvements in care. However, the cost of branded medications is too high for resource-limited countries, where most persons with HIV/AIDS live. Generic drugs dramatically lower the cost of care; however, their safety and efficacy must be ensured and maintained. Proven bioavailability and bioequivalence, in addition to satisfactory manufacturing, distribution, and administration, are keys to successfully implementing the use of qualified generic ARVs. Agencies such as the US Food and Drug Administration (FDA), European Medicines Agency (EMEA), and the World Health Organization (WHO), continue to strengthen the surveillance process through which qualified generic and branded drugs are provided worldwide. Generic drugs have the potential to cause harm if rigorous standards for their use are not followed, but those that are qualified offer great promise in the treatment of HIV/AIDS.