Cycloserine

Generic Name: cycloserine

Over-the-Counter (OTC)

Brand Names:

Cycloserine

DESCRIPTION D -Cycloserine, (R)-4-amino-3-isoxazolidinone, is a broad-spectrum antibiotic that is produced by a strain of Streptomyces orchidaceus and has also been synthesized. Cycloserine is a white to off-white powder that is soluble in water and stable in alkaline solution. It is rapidly destroyed at a neutral or acid pH. Cycloserine has a pH between 5.5 and 6.5 in a solution containing 100 mg/mL. The molecular weight of cycloserine is 102.09, and it has an empirical formula of C 3H6N2O 2 .

Overview

DESCRIPTION D -Cycloserine, (R)-4-amino-3-isoxazolidinone, is a broad-spectrum antibiotic that is produced by a strain of Streptomyces orchidaceus and has also been synthesized. Cycloserine is a white to off-white powder that is soluble in water and stable in alkaline solution. It is rapidly destroyed at a neutral or acid pH. Cycloserine has a pH between 5.5 and 6.5 in a solution containing 100 mg/mL. The molecular weight of cycloserine is 102.09, and it has an empirical formula of C 3H6N2O 2 .

Uses

INDICATIONS AND USAGE Cycloserine is indicated in the treatment of active pulmonary and extrapulmonary tuberculosis (including renal disease) when the causative organisms are susceptible to this drug and when treatment with the primary medications (streptomycin, isoniazid, rifampin, and ethambutol) has proved inadequate. Like all antituberculosis drugs, cycloserine should be administered in conjunction with other effective chemotherapy and not as the sole therapeutic agent. Cycloserine may be effective in the treatment of acute urinary tract infections caused by susceptible strains of gram-positive and gram- negative bacteria.

Dosage

DOSAGE AND ADMINISTRATION Cycloserine is effective orally and is currently administered only by this route. The usual dosage is 500 mg to 1 g daily in divided doses monitored by blood levels. 1 The initial adult dosage most frequently given is 250 mg twice daily at 12-hour intervals for the first 2 weeks. A daily dosage of 1 g should not be exceeded.

Side Effects

ADVERSE REACTIONS Most adverse reactions occurring during therapy with cycloserine involve the nervous system or are manifestations of drug hypersensitivity. The following side effects have been observed in patients receiving cycloserine: Nervous system symptoms (which appear to be related to higher dosages of the drug, i.e., more than 500 mg daily) • Convulsions • Drowsiness and somnolence • Headache • Tremor • Dysarthria • Vertigo • Confusion and disorientation with loss of memory • Psychoses, possibly with suicidal tendencies • Character changes • Hyperirritability • Aggression • Paresis • Hyperreflexia • Paresthesia • Major & minor (localized) clonic seizures • Coma Cardiovascular: Sudden development of congestive heart failure in patients receiving 1 to 1.5 g of cycloserine daily has...

Warnings

WARNINGS Administration of cycloserine should be discontinued or the dosage reduced if the patient develops allergic dermatitis or symptoms of CNS toxicity, such as convulsions, psychosis, somnolence, depression, confusion, hyperreflexia, headache, tremor, vertigo paresis, or dysarthria. The toxicity of cycloserine is closely related to excessive blood levels (above 30 mcg/mL), as determined by high dosage or inadequate renal clearance. The ratio of toxic dose to effective dose in tuberculosis is small. The risk of convulsions is increased in chronic alcoholics. Patients should be monitored by hematologic, renal excretion, blood level, and liver function studies. CONTRAINDICATIONS Administration is contraindicated in patients with any of the following: • Hypersensitivity to cycloserine • Epilepsy • Depression, severe anxiety, or psychosis • Severe renal insufficiency • Excessive concurrent use of alcoho

Storage

HOW SUPPLIED Cycloserine is available as a 250 mg capsule with an opaque red cap and opaque gray body imprinted with “PGC” and “F04” in edible black ink on both the cap and the body. Cycloserine Capsules, USP are supplied in cartons of 3 cards. Each card is a ten-capsules blister card as follows: NDC 43598-235-31: carton with 3 cards. NDC 43598-235-10 (ten 250mg capsules per card).

Frequently Asked Questions

What is Cycloserine used for?

INDICATIONS AND USAGE Cycloserine is indicated in the treatment of active pulmonary and extrapulmonary tuberculosis (including renal disease) when the causative organisms are susceptible to this drug and when treatment with the primary medications (streptomycin, isoniazid, rifampin, and ethambutol) has proved inadequate. Like all antituberculosis drugs, cycloserine should be administered in conjunction with other effective chemotherapy and not as the sole therapeutic agent. Cycloserine may be effective in the treatment of acute urinary tract infections caused by susceptible strains of gram-positive and gram- negative bacteria.

What are the side effects of Cycloserine?

ADVERSE REACTIONS Most adverse reactions occurring during therapy with cycloserine involve the nervous system or are manifestations of drug hypersensitivity. The following side effects have been observed in patients receiving cycloserine: Nervous system symptoms (which appear to be related to higher dosages of the drug, i.e., more than 500 mg daily) • Convulsions • Drowsiness and somnolence • Headache • Tremor • Dysarthria • Vertigo • Confusion and disorientation with loss of memory • Psychoses, possibly with suicidal tendencies • Character changes • Hyperirritability • Aggression • Paresis • Hyperreflexia • Paresthesia • Major & minor (localized) clonic seizures • Coma Cardiovascular: Sudden development of congestive heart failure in patients receiving 1 to 1.5 g of cycloserine daily has...

What are the important warnings for Cycloserine?

WARNINGS Administration of cycloserine should be discontinued or the dosage reduced if the patient develops allergic dermatitis or symptoms of CNS toxicity, such as convulsions, psychosis, somnolence, depression, confusion, hyperreflexia, headache, tremor, vertigo paresis, or dysarthria. The toxicity of cycloserine is closely related to excessive blood levels (above 30 mcg/mL), as determined by high dosage or inadequate renal clearance. The ratio of toxic dose to effective dose in tuberculosis is small. The risk of convulsions is increased in chronic alcoholics. Patients should be monitored by hematologic, renal excretion, blood level, and liver function studies. CONTRAINDICATIONS Administration is contraindicated in patients with any of the following: • Hypersensitivity to cycloserine • Epilepsy • Depression, severe anxiety, or psychosis • Severe renal insufficiency • Excessive concurrent use of alcoho

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.