A 45-year-old woman with 65 kg weight was a case of recently diagnosed TB/HIV co-infection. She was prescribed zidovudine (300 mg) + lamivudine (150 mg) + efavirenz (600 mg) and Category 2 DOTS Regimen: 2 (HRZES)3/1 (HRZE)/5 (HRE)3. She presented with nail pigmentation after 6 weeks of ingestion of above-mentioned therapy. It first appeared in greater toe nail, gradually increased in intensity over 2 weeks' time. Local examination revealed diffuse bluish-brown discoloration of thumbnails. It did not disappear on compression of nail plate. Nails were brittle and the pattern of nail pigmentation was diffuse in nature and there was no evidence of skin and mucus membranes being involved.
She had no previous history of any such ADR, hypertension, diabetes mellitus, any other chronic organic diseases, smoking or alcohol intake. The patient had even no history of any regular or long-term use of any drug. ELISA for HIV was positive. Polymerase chain reaction for RNA was positive. CD4+ count was 138 cells/mm3. Erythrocyte sedimentation rate : 47 mm (1 h), Mantoux test, and sputum samples for acid fast bacilli for three consecutive days were positive. A chest radiograph showed bilateral hilar opacities in both the lungs. A computed tomography scan of chest disclosed mediastinal lymphadenopathy.
Hemoglobin, 10.8 g%; total leukocyte count, 10,400/cumm; platelet count, 2.4 lac/cumm; blood urea, 19 mg/dl; serum creatinine, 0.8 mg/dl; blood sugar, 98 mg%; serum cholesterol, 180 mg%; triglycerides, 155 mg%; clotting and bleeding time was normal; serum uric acid, 6.6 mg/dl; bilirubin, 1 mg/dl; serum glutamic-oxaloacetic transaminase, 45 U/L; and serum glutamic pyruvic transaminase, 36 U/L. Thyroid profile was normal. Electrocardiogram and ultra-sonography were normal.
Temporal association between starting zidovudine HAART regimen and subsequent development of this ADR and appearance of such ADR could not be explained by any concurrent drug, disease, and chemical. Thus, a possible diagnosis of zidovudine-induced nail pigmentation was established. The de-challenge and re-challenge could not be done due to ethical and clinical constraint. No dose-related study was done in the current case because of similar reasons. The Naranjo's score was 7 and WHO causality assessment showed probable correlation with the current adverse event. Severity of the reaction was assessed using Hartwig ADR severity assessment scale which classified the said ADR into nonserious. Due to nonserious nature of the reaction, no change in the treatment was done in the current case except counseling.