Table 2.

Antituberculosis agents (13–15, 47, 68)

First-line agents	Metabolism	Side effects
isoniazid	hepatic acetylated	hepatitis, peripheral neuropathy (prevented with pyridoxine 25 or 50 mg daily)
rifampin/rifabutin, rifapetine	hepatic	hepatitis, orange body fluids
pyrazinamide	hepatic; renal excretion	hepatic; renal excretion
ethambutol	renal excretion	retrobulbar neuritis in renal failure
streptomycin	renal excretion	ototoxicity, nephrotoxicity, peripheral neuropathy, pain at injection site, vestibular toxicity
Second-line agents
ciprofloxacin, ofloxacin, levofloxacin, moxifloxacin, gatifloxacin	renal excretion	mild GI distress, psychosis, seizure (mainly in elderly),QT interval prolongation, dysglycemia
kanamycin, amikacin, capreomycin	renal excretion	ototoxicity, nephrotoxicity, peripheral neuropathy, pain at injection site, vestibular toxicity
ethionamide/prothionamide	hepatic; renal excretion	frequent GI distress, metallic taste, hypothyroidism especially with PAS
cycloserine	renal excretion	neurologic/psychiatric: irritability, aggression, headaches, tremors; uncommon: psychosis, neuropathy, seizures
terizidone	renal excretion	GI distress, headache, seizures, dysarthria
para-aminosalicylic acid (PAS)	hepatic; renal excretion	frequent GI distress, hypothyroidism especially with ETO; uncommon: hepatitis
thiacetazone	GI excretion	GI distress, vertigo, conjunctivitis, hypersensitivity reactions including TEN, SJS especially in HIV infection
Third-line agents (limited data)
linezolid	renal excretion	lowers seizure threshold, myelosuppression if duration >2 weeks, peripheral neuropathy; serotonin syndrome
clofazimine	GI excretion	GI distress; reddish brown discoloration of skin, which slowly resolves after discontinuation of drug
amoxicillin/clavulanate	hepatic; renal excretion	rash, GI distress
clarithromycin	hepatic	GI distress, headache; rare: hepatic failure

Abbreviations: GI, gastrointestinal; ETO, ethionamide; TEN, toxic epidermal necrolysis; SJS, Stevens-Johnson syndrome.