Question
A Resident surgeon consults a physician with the following problem: During a surgical procedure he got exposed to a 26-year-old female patient’s blood and saliva through a piercing injury on the finger. A needle had penetrated across his gloves and skin to a depth of 2–3 mm, but was withdrawn immediately and the area washed under running water. On enquiry, the patient revealed that one year back she had tested HIV (Human Immunodeficiency Viru
- (a) Classify Antiretroviral drugs with two examples each. ( 4 mark(s)
- (b) Describe in detail the mechanism of action, uses and adverse effects any two drug groups. ( 6 mark(s)
- (c) Add a note on the drugs used for post exposure HIV prophylaxis. ( 3 mark(s)
- (d) Measures to be practiced to avoid needle prick injury. 2 mark(s)
Answer
a) Classification of antiretroviral drugs, two examples each
| Class | Examples |
|---|---|
| NRTIs | Zidovudine, Tenofovir |
| NNRTIs | Efavirenz, Nevirapine |
| Protease inhibitors | Ritonavir, Atazanavir |
| Integrase inhibitors | Dolutegravir, Raltegravir |
b) Two drug groups — mechanism, uses, adverse effects NRTIs: nucleoside analogues that, after intracellular phosphorylation, are incorporated into proviral DNA by reverse transcriptase, acting as chain terminators. Used as the “backbone” of combination therapy. Zidovudine’s defining adverse effect is bone marrow suppression (off-target mitochondrial DNA polymerase gamma inhibition).
Integrase inhibitors: block HIV integrase, the enzyme that inserts reverse-transcribed proviral DNA into the host genome — an earlier point in the life cycle than protease inhibitors act. Now generally preferred first-line, given potency, tolerability, and high barrier to resistance. Generally well tolerated; adverse effects include headache, insomnia, and rare hypersensitivity.
c) Post-exposure HIV prophylaxis Started after significant exposure (this resident’s needlestick injury), ideally within hours and no later than 72 hours, continued for 28 days. A standard regimen combines three antiretroviral drugs, commonly two NRTIs plus an integrase inhibitor (e.g. Tenofovir + Emtricitabine + Dolutegravir) — the same combination-therapy resistance-prevention logic as standard HIV treatment. Immediate first-aid at the time of injury — washing the area with soap and water without aggressive scrubbing — plus prompt reporting for risk assessment (source patient’s HIV status, exposure depth/severity) determines whether PEP is indicated; here, the known HIV-positive source and penetrating injury with visible blood exposure warrant starting PEP promptly.
d) Measures to avoid needle-prick injury
- Never re-cap used needles by hand (“no-touch” technique or dedicated re-capping devices only)
- Use safety-engineered devices (retractable needles, needleless systems) where available
- Dispose of sharps immediately into a puncture-resistant sharps container at the point of use, never overfilled
- Double-gloving during high-risk procedures
- Adequate lighting and unhurried technique during procedures involving sharps
- Regular staff training on safe sharps handling and post-exposure reporting protocols