Pharmacoepidemiology of antiretroviral drugs in a teaching hospital in Lagos, Nigeria

Prevalence and characteristics of hepatitis B and D virus infections among HIV-positive individuals in Southwestern Nigeria

Background

Coinfections of HIV-positive individuals with Hepatitis B and D virus (HBV and HDV) are common and can be associated with rapid liver damage. Several antiretroviral drugs for HIV exhibit anti-HBV effect; however, the selection of HBV drug resistance mutations (DRMs) in individuals under HIV antiretroviral therapy (ART) has been reported but rarely in Nigeria. In this study the HBV/HDV prevalence and HBV DRMs in HIV-positive individuals in Southwestern Nigeria were assessed.

Methods

Plasma samples collected from 310 HIV-positive individuals including 295 ART-experienced and 15 ART-naïve persons attending the HIV clinic in three south-western states of Nigeria between June 2017 and August 2017 were analysed by ELISA for HBsAg and anti-HDV. The presence of HDV RNA and HBV DNA was analysed by (RT)-PCR followed by sequencing and phylogenetic analyses for genotyping. The HBV reverse transcription (RT) region was amplified and sequenced for the analysis of drug resistance mutations.

Results

Overall, 16.1% (n = 50/310) of the HIV-positive individuals were positive for HBsAg, most of which were ART-experienced (94.0%; n = 47/50). From the 50 HBsAg-positive samples, 72.0% (n = 36/50) were positive for HBV DNA and 16.0% (n = 8/50) had detectable HDV RNA while 5.6% (n = 2/36) of the HBV-DNA positive samples had anti-HDV total antibodies. Sequences were available for 31/36 of the HBV DNA-positive and 3/8 HDV RNA-positive samples. HBV DNA-positive samples were characterised as HBV genotype E infections exclusively, while HDV genotype 1 was detected in the HDV RNA-positive samples. HBV DRMs V173L, L180M, S202I and M204V/I, which are associated with lamivudine resistance, were detected in 32.2% (n = 10/31) of the HBV DNA-positive samples. Most of these mutations (90.0%; n = 9/10) were present in the ART-experienced cohort.

Conclusions

This study indicates that HBV/HDV coinfections are common in HIV-positive individuals under ART in Nigeria. Furthermore, a high proportion of HBV DRMs which potentially compromise future treatment options were detected, underscoring the need for HBV screening prior to starting ART. Further studies should be performed to monitor a possible increase in the spread of HDV among populations at risk of HIV and HBV infections.

High frequency of drug resistance mutations in the HBV genome in ART-experienced HIV-coinfected patients in southwestern Nigeria

BACKGROUND

HBV and HIV infections are highly endemic in sub-Saharan Africa and Nigeria while HBV-HIV coinfection is not uncommon. Antiretroviral (ART)-treatment for HIV can affect HBV whereby antiviral resistance mutations in the HBV genome can be selected. Here, we determined the prevalence of resistance mutations among ART-experienced and ART-naive HIV-HBV-coinfected patients in southwestern Nigeria.

METHODS

A total of 81 serum samples from HBV-HIV-coinfected patients who were either ART-naive or received lamivudine (3TC)-containing ART-therapy and HBV-monoinfected patients were analysed. Hepatitis B surface antigen (HBsAg) was detected using ELISA. HBV-positive samples were confirmed by PCR amplification of the surface and polymerase regions. Mutations conferring drug resistance to HBV were analysed by direct sequencing. Phylogenetic analysis was performed to identify the HBV genotype.

RESULTS

Of the 81 HBsAg-positive samples, 27 had detectable HBV DNA by real-time PCR with mean viral loads of 6.77 log IU/ml. Phylogenetic analyses showed a predominance of HBV genotype E. A high prevalence (22.2%; 6/27) of HBV resistance mutations among ART-experienced HBV-HIV-coinfected patients was detected. However, a relatively high selection rate of resistance mutations in drug-naive HIV-HBV-coinfected (3.7%; 1/27) and in HBV-monoinfected patients, potential drug resistance mutations (7.4%; 2/27) were also observed. HBV polymerase amino acid substitutions found included rtV173L, rtL180M, rtM204V, rtK212R, rtS213T, rtV214A, rtL229V and rtP237A/S.

CONCLUSIONS

Drug resistant mutations were detected frequently in ART-experienced HIV-HBV patients. Well-coordinated antiviral therapy for HIV patients coinfected with HBV should include proper HBV diagnosis and resistance testing to minimize the emergence and spread of antiviral drug resistance.

A Retrospective Review of Serious Adverse Drug Reaction Reports in the Nigerian VigiFlow Database from September 2004 to December 2016

BACKGROUND

Adverse drug reactions (ADRs) are a source of concern in healthcare as they negatively affect patients. Serious adverse drug reactions (SADRs) have an even greater impact on patients and the system in terms of morbidity and financial burden. The establishment of National Pharmacovigilance Centers (NPCs) has enhanced ADR reporting in Africa. The Nigerian Pharmacovigilance Centre has been collecting ADR reports using VigiFlow since 2004.

OBJECTIVE

The aim of this study was to identify and analyze SADR reports in the Nigerian VigiFlow database in order to profile the patients with SADRs, the medicines most implicated, system organ classes (SOCs) affected, outcome of such reactions, including fatalities, and ADR reporting trends over the years. We also looked at the data elements provided in the reports as a proxy measure of report quality.

METHOD

We retrospectively assessed all individual case safety reports (ICSRs) received by the NPC in Nigeria and entered into VigiFlow as SADR reports between September 2004 and December 2016. We defined SADR as any untoward reaction to any medicine dose that resulted in death, required in-patient hospitalization or prolongation of existing hospitalization, resulted in congenital anomaly, persistent or significant disability/incapacity or was life-threatening. The suspected SADRs were analyzed at the Medical Dictionary for Regulatory Activities SOC and Preferred Term levels.

RESULTS

A total of 11,222 ICSRs were entered into VigiFlow during the study period, of which 298 (3%) were classified as SADR reports. Adults were the most affected (244/282; 87%). The median number of medicines per report was 3 (interquartile range = 2-4.75). Nevirapine (36/336; 11%), as a single entity, was the most reported medicine. Human immunodeficiency virus (HIV) infection affected 128/232 (55%) of those with SADRs. There was no statistically significant association between the number of reactions per report and sex of the patients (p = 0.280), their age groups (p = 0.670), or the number of medicines per report (p = 0.640). Hospitalization was the most frequently cited reason for classifying a report as serious (151/276; 53%) and death was reported in 48 cases (48/283; 17%). Based on the SOC, skin and subcutaneous tissue disorders (139/550; 25%) was the most affected, while anemia (55/550; 10%) was the most reported specific reaction. A substantial number of patients (107/256; 42%) either recovered fully or were recovering from the SADRs. The number of SADR reports received varied by year with no consistent trend.

CONCLUSION

There is under-reporting of ADRs in the Nigerian VigiFlow^® database, particularly SADRs and those involving pediatric and geriatric age groups. Given that over half of the SADR reports involved antiretroviral drugs, it is imperative to increase the surveillance of ADRs related to this class of drugs through regular clinical assessment of reports and provision of feedback on the findings to healthcare providers. Direct consumer reporting should also be encouraged as a means of increasing ADR reporting.

Antiretroviral-induced adverse drug reactions in HIV-infected patients in Mali: a resource-limited setting experience

Background

There are few reports in the literature from sub-Saharan Africa (SSA) regarding antiretroviral-induced adverse drug reactions (ADRs). Antiretroviral therapy (ART) is now widely available in SSA, and ADRs during HIV infection are also frequent. In this study, we reported the frequency and risk factors of ART-induced ADRs in a Malian population.

Methods

This prospective cohort study was performed in the HIV Care and Counseling Centre (CESAC) of Mali from 2011 to 2012. Adult patients infected with HIV and who had recently started ART were included and followed-up clinically Were included in this study, adult patients living with HIV and had recently started ART who were followed up for at least 6 months to determine the incidence of ADRs using Naranjo's classification scale.

Results

During this study, 357 (42.3%) patients presented ADRs (40.1% of our patients (n=338) experienced at least one ADR, and 2.2% (n=19) experienced at least two ADRs). The prevalence of ADRs by organ system was: 45.9% neurological (n=164); 29.4% metabolic (blood chemistry) (n=105); 15.4% hematological (n=55). High probable rate of ADR was observed as indicated by the Naranjo score in 83.7% of the cases. Zidovudine (AZT) and stavudine (d4T) use was identified as a risk factor for either anaemia or peripheral neuropathy whereas nevirapine (NVP) and female gender were risk factors for skin reactions. Patients with advance disease had the highest rate of ADRs compared to the others.

Conclusions

Based on the Naranjo probability scale, our data show that ADRs such as peripheral neuropathy and anemia are very frequent. These ADR was linked to AZT and D4T. Our findings highlight the need for active monitoring, continuous pharmacovigilance of ART and change of some ART drug in this population.

Singularities of nevirapine metabolism: from sex-dependent differences to idiosyncratic toxicity

Nevirapine (NVP) is a first-generation non-nucleoside reverse transcriptase inhibitor widely used for the treatment and prophylaxis of human immunodeficiency virus infection. The drug is taken throughout the patient's life and, due to the availability of an extended-release formulation, it is administered once daily. This antiretroviral is one of the scarce examples of drugs with prescription criteria based on sex, in order to prevent adverse reactions. The therapy with NVP has been associated with potentially life-threatening liver and idiosyncratic skin toxicity. Multiple evidence has emerged regarding the formation of electrophilic NVP metabolites as crucial for adverse idiosyncratic reactions. The formation of reactive metabolites that yield covalent adducts with proteins has been demonstrated in patients under NVP-based treatment. Interestingly, several pharmacogenetic- and sex-related factors associated with NVP toxicity can be mechanistically explained by an imbalance toward increased formation of NVP-derived reactive metabolites and/or impaired detoxification capability. Moreover, the haptenation of self-proteins by these reactive species provides a plausible link between NVP bioactivation and immunotoxicity, further supporting the relevance of this toxicokinetics hypothesis. In the current paper, we review the existing knowledge and recent developments on NVP metabolism and their relation to NVP toxicity.

Patterns of adverse drug reaction signals in NAFDAC pharmacovigilance activities from January to June 2015: safety of drug use in Nigeria

Adverse drug reactions (ADRs) are expected to be associated with an economic drain on the healthcare systems. The study was carried out to determine the occurrence of ADRs reported to NAFDAC Pharmacovigilance from January to June 2015, to illustrate the pattern of organ system affected by ADRs, to assess the completeness of ADR report, to determine the relationship between the occurrence of ADRs with suspect drugs and the use of concomitant drugs as well as to generate possible signals from the reported ADRs. A total number of 921 ADR cases reported from January to June 2015 were analyzed using SPSS version 22. A higher percentage of ADR reports were seen in females (65.5%). The highest percentages of reports (45.6%) were from the age range of 21‐40 years, most of the suspected drugs reported had both NAFDAC (50.2%) and batch number identification (65.6%). HIV (56.9%) was the most prevalent indication reported for using the suspected drug; Zidovudine/Lamivudine/Nevirapine combination (16.9%) was reported as the suspected drug with the highest occurrences of ADRs and generalized body itching (6.9%) as the most prevalent ADR. “General disorders” (47.3%) was the most predominant organ system affected by ADRs and Pharmacists were revealed as the highest reporters of ADRs (80.2%). Overall, patients on ARVs should be vigilantly followed up as they are mostly prone to ADRs. Adverse drug reaction reporting systems need to be robust and complete in order to be able to detect new drug alerts, possible signals and improve pharmacovigilance

Patterns of adverse drug reaction signals in NAFDAC Pharmacovigilance activities from September to November, 2014

BACKGROUND

Adverse drug reaction signals are reported information on possible causal relationships between an adverse event and a drug. The National Pharmacovigilance Centre (NPC) in Nigeria has over 3,000 reported adverse drug reaction cases which have been adequately entered into the ADR data bank.

OBJECTIVE

Data mining of ADR reports from September to November, 2014 were carried out in this present study with the intention to describe the pattern of ADRs and generate possible signals.

METHODS

A total of about 100 reported cases with arrays of adverse drug reactions were reported between September and November, 2014 and the data were analyzed using SPSS version 17.

RESULTS

Efavirenz/Tenofovir/Lamivudine combination was the highest reported drugs (24.2%) while efavirenz alone was reported in 8 times (8.8%) and HIV (63.3%) was the highest reported indication of drug use. Efavirenz caused central nervous system adverse reactions as revealed in the ADRs analyses. Zidovudine/Lamivudine/Nevirapine combination in concomitant use with Cotrimoxazole were reported 8 times with generalized maculopapular rashes on the trunk with some area of hyper pigmentation with intense itching documented twice and big/swollen rashes all over the faces. Zidovudine was also reported four times to cause severe anaemia.

CONCLUSION

More surveillance is advocated so as to ascertain the consistency of the observed ADRs and thereafter establish appropriate signals.