Complete adverse effect profile including incidence rates and management
Important Safety Information
This is not a complete list of all possible side effects. Contact your healthcare provider if you experience any unexpected symptoms. For serious or life-threatening side effects, seek emergency medical attention immediately.
ADVERSE REACTIONS The most frequent reactions are those affecting the nervous system and the liver.
Nervous System Reactions Peripheral neuropathy is the most common toxic effect.
It is dose-related, occurs most often in the malnourished and in those predisposed to neuritis (e.g., alcoholics and diabetics) and is usually preceded by paresthesias of the feet and hands.
The incidence is higher in "slow inactivators".
Other neurotoxic effects, which are uncommon with conventional doses, are convulsions, toxic encephalopathy, optic neuritis and atrophy, memory impairment and toxic psychosis.
Cerebellar syndrome, which may include abnormal motor coordination manifesting as gait, trunk, and limb ataxia, dysmetria and dysdiadochokinesia, intention tremor, dysarthria, or nystagmus, have been reported in post marketing case reports (see WARNINGS ).
Hepatic Reactions See boxed warning .
Elevated serum transaminase (SGOT;
SGPT), bilirubinemia, bilirubinuria, jaundice and occasionally severe and sometimes fatal hepatitis.
The common prodromal symptoms of hepatitis are anorexia, nausea, vomiting, fatigue, malaise and weakness.
WARNINGS See the boxed warning .
Severe Cutaneous Adverse Reactions Severe cutaneous adverse reactions (SCARs) including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP) have been reported with the use of isoniazid (see ADVERSE REACTIONS ).
Symptoms can be serious and potentially life threatening.
If symptoms or signs of SCARs develop, discontinue isoniazid tablets immediately and institute appropriate therapy.
Cerebellar Syndrome Cerebellar syndrome which may include abnormal motor coordination presenting as gait, trunk, and limb ataxia, dysmetria and dysdiadochokinesia, intention tremor, dysarthria, or nystagmus, has been reported in postmarketing case reports with the use of isoniazid (see ADVERSE REACTIONS ).
Like all medications, Isoniazid can cause side effects. However, not everyone who takes this medication will experience them. Many side effects are dose-dependent and may improve as your body adjusts to the medication. Others may require dose adjustment or medical attention.
Contact your healthcare provider promptly if you experience:
Seek immediate emergency medical care if you experience signs of: