Insight into drug toxicity


By Catherine Murombedzi

“LAUGHTER is the only medicine without side effects,” — L. Alder.
We have often heard that laughter is the best medicine. However, one Nyasha said whoever said that had not experienced our African laugh. He argues that one can end up with severe chest pains as a result of excessive laughter. I will stick to the original saying.
Wikipedia states: “Medicine is the science and practice of diagnosis, treatment and prevention of diseases.”
Medicine has existed for thousands of years, during most of which it was an art (an area of skill and knowledge) frequently having connections to the religious and philosophical beliefs of local culture where practiced.
This instalment looks at anti-retroviral therapy (ART) also widely known as ARVs.
All medication has side effects. This was said by Dr Regis Choto, National ART co-ordinator in the Ministry of Health and Child Care addressing a Meaningful Involvement of People Living with AIDS (MIPA) forum, hosted by the National AIDS Council (NAC) in Masvingo, recently.
He further stated that medicines alter our ability to live with disease thereby generally increasing the duration of our lives.
He pointed out that medication, if taken incorrectly and is not sufficiently monitored results in error or when there is communication challenges, it can fail to achieve the desired results.
He stressed that the need to take medication far outweighed side effects, hence the need to keep taking the medication or have the medication causing the severe side effects altered or totally replaced by a more tolerable regimen.
He gave an insight into the use of ARVs in restoring lost immunity due to the human-immune virus (HIV).
Currently, there is no cure to HIV, only successful suppression of the virus that one is able to live a normal life as experienced before infection.
Everyone who tests HIV positive is commenced on ARVs without a need to undergo laboratory tests.
The tests can be done when one is already on treatment.
The World Health Organisation (WHO) urges ‘test and treat’ for all testing HIV positive. Symptom-directed laboratory monitoring for safety and toxicity can be done for those already receiving ART.
All ARVs have potential side effects.
However, the need to take the medication surpasses the outcome.
When taking ARVs, it is important to identify risk factors early to avoid severe side effects.
“Early diagnosis of side effects is important as majority of these toxicities are reversible if appropriately managed,” said Dr Choto.
He said Zimbabwe was doing well on the 90-90-90 target but needed to keep the tempo up on the first 90.
“As a country, we have fared well on the 90-90-90 target. However, it is on the first 90 that we need to up the beat. As stated, 90 percent of our population needs to know their HIV status.
“This is only possible when everyone gets tested. We need to call on all stakeholders, partners and community champions to keep the testing drive in gear. If that figure is not achieved, then there is a danger of derailing the remaining two,” he added.
The second 90 states that, of the tested population who have been found to have the HIV virus, 90 percent must be commenced on ARVs.
The third 90 is for the group on ART to get a suppressed viral load. A suppressed viral load means no HIV virus can still be transmitted.
This is achieved if one is taking medication correctly, is monitored and the medication is working efficiently.
Patient retention is of great importance as follow-up mechanism need to ensure that clients are not lost on the way.
“The issue is not just to commence patients on treatment. We have to make sure that they are retained. Women, by nature, report earlier for treatment and have better retention as compared to males,” said Dr Choto.
He pointed out that the key considerations are treatment optimisation, safety, efficacy, affordability, reduced pill burden and harmonisation across all age-groups.
Affordability, cost of ARVs, generic formulations, availability.
Fixed dose combinations, as opposed to single dose where a person ends up taking three tablets; currently the three doses have been combined into one.
Country’s preferred option combination.
“Newer ARVs like Dolutegravir (DTG) that underwent trials in South Africa and other selected few countries in patients who were failing on other ART drugs has been shown to have less side effects. However, only time will tell on their safety in our population,” said Dr Choto.
DTG is taken once a day.
It has fewer drug interaction. I
t is taken without regard to meals, is well tolerated, needs no pharmacological boosting and has a high barrier to resistance.
However, Zimbabwe is not going to use DTG in the public hospitals this year as stocks are ordered annually and the current stock is up to year end.
The presentation by Dr Choto was on behalf of Newlands Clinic, Harare, where specific drug reactions in some patients were noted.
The spectrum of adverse events, severity and occurrence were noted.
The clinic has 6 000 clients, has a laboratory on site and monitors all for quality treatment.
Of the listed in occurrence were:
l Early onset and potentially life threatening/fatal
lAcute or short-term
l Occurrence within first few months after starting ARVs was seen to likely affect adherence
l Chronic or long-term which was anticipated in all patients on long-term treatment
The clinic recommends that of the major ARVs used in Zimbabwe, if a client has severe reactions, a replacement must be used.
Newlands Clinic noted five hepatotoxicity cases from using Effavirenz (pills) in its clients. It noted four cases of dizziness on the same regimen.
It had five anaemia cases on clients on Azidothymidine best known as AZT. The clinic noted three renal cases of clients on TDF.
The clinic noted lipodystrophy from four clients on AZT too. All the patients were moved to drugs that managed their needs better with less severe side effects.
As stated, early diagnosis of side effects is of paramount importance as the majority of these toxicities are reversible if properly managed.


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