Drugs and availability	Daily dosage	Major toxicities and concerns	Cost*	Monitoring
Zidovudine (AZT, ZDV; Retrovir), 100 mg, 300 mg capsules; 50 mg per 5 mL syrup; 10 mg per mL IV infusion	Adults: 200 mg every 8 hours or 300 mg every 12 hours Children 3 months to 12 years: 180 mg per m2 every 6 hours; maximum: 200 mg every 6 hours	Bone marrow suppression (severe anemia, granulocytopenia, thrombocytopenia), myopathy, myositis	100 mg, #180, $2 87 300 mg, #60, $287 Syrup: 8 oz, $38	Periodic CBC
Didanosine (ddI; Videx), 25 mg, 50 mg, 100 mg, 150 mg chewable tablets; 100 mg, 167 mg, 250 mg powder packets; powder for oral solution: 2 g, 4 g	Tablets, powder packets:	Pancreatitis, peripheral neuropathy, liver failure, retinal depigmentation and change in vision (in children) Must be taken on empty stomach, 2 hours after or 1 hour before food.	100 mg, #120, $186 250 mg packets, #60, $233 2 g powder, $31 4 g powder, $62	Children: dilated retinal examination every 6 months
	≥60 kg: 200 mg every 12 hours
	<60 kg: 125 mg every 12 hours
	Oral solution:
	≥60 kg: 250 mg every 12 hours†
	<60 kg: 167 mg every 12 hours†
Zalcitabine (DDC; Hivid), 0.750 mg, 0.375 mg tablets	≥30 kg: 0.75 mg every 8 hours <30 kg: 0.375 mg every 8 hours	Peripheral neuropathy (22 to 35%), pancreatitis, esophageal ulcers, stomatitis, cardiomyopathy, hepatic failure	0.75 mg, #90, $207 0.375 mg, #90, $165	Periodic CBC, chemistry profile, amylase determination
Lamivudine (3TC; Epivir), 150 mg tablets; 10 mg per mL oral solution	>50 kg: 150 mg every 12 hours‡	Headache, insomnia, fatigue, peripheral neuropathy, myalgia, pancreatitis	150 mg, #60, $230 Oral solution: 8 oz, $61	—
	<50 kg: 2 mg per kg every 12 hours‡
	3 months to 12 years: 4 mg per kg twice daily
Stavudine (D4T; Zerit), 15 mg, 20 mg, 30 mg, 40 mg capsules; 1 mg per mL oral solution	≥60 kg: 40 mg every 12 hours	Peripheral neuropathy (15 to 21%), hepatotoxicity, anemia, pancreatitis	40 mg, #60, $244 30 mg, #60, $235	Periodic liver function tests∥
	30 to 59 kg: 30 mg every 12 hours
	<30 kg: 1 mg per kg every 12 hours