TINIDAZOLE (tin'i-da-zole)
Tindamax Classifications: azole antibiotic; antiprotozoal; amebicide; Therapeutic: azole antibiotic; antiprotozoal; amebicide Prototype: Metronidazole Pregnancy Category: D first trimester; C second and third trimester
|
Availability
250 mg, 500 mg tablets
Action
Made from cell extracts of Trichomonas. Tinidazole is effective against dividing and nondividing cells of targeted bacteria and protozoa. It inhibits formation
of their DNa helix and thus inhibits DNA synthesis of these organisms. This leads to bacterial and protozoal cell death.
Therapeutic Effect
Demonstrates activity against infections caused by protozoa and anaerobic bacteria.
Uses
Treatment of trichomoniasis, giardiasis, amebiasis, bacterial vaginosis, and amebic liver abscess.
Contraindications
First trimester of pregnancy (category D), second and third trimesters pregnancy (category C); known hypersensitivity to
tinidazole or other azole antibiotics (e.g., metronidazole); lactation within 72 h of tinidazole use; children <3 y.
Cautious Use
CNS diseases, liver dysfunction, alcoholism, ethanol intoxication; hematologic disease; neurologic disease; bone marrow
depression; dialysis; candidiasis.
Route & Dosage
Giardiasis Adult: PO 2 g as single dose Child (≥ 3 y): PO 50 mg/kg (up to 2 g) as single dose
Intestinal Amebiasis Adult: PO 2 g once daily for 3 d Child (≥ 3 y): PO 50 mg/kg/d (up to 2 g/d) once daily for 3 d
Amebic Liver Abscess Adult: PO 2 g once daily for 35 d Child (≥3 y): PO 50 mg/kg/d (up to 2 g/d) once daily for 35 d
Trichomoniasis Adult: PO 2 g as single dose
Bacterial Vaginosis Adult: PO 2 g q.d. x 2 d OR 1 g q.d. x 5 d
Hemodialysis: If dose given on dialysis day, give supplemental dose (? regular dose) post-dialysis
|
Administration
Oral
- Give with food to minimize GI distress; may be crushed in artificial cherry syrup if tablets cannot be swallowed whole.
- If given on a dialysis day, add a 50% dose of tinidazole at the end of hemodialysis.
- Separate the dosing of cholestyramine and tinidazole by 24 h when used concurrently.
- Do not give within 2 wk of the last dose of disulfiram.
- Store at 15°30° C (59°86° F). Protect from light.
Adverse Effects (≥1%)
Body as a Whole: Weakness,
fatigue, malaise.
CNS: Dizziness, headache.
GI: Metallic/bitter taste, nausea, anorexia, dyspepsia, cramps, epigastric discomfort, vomiting,
constipation.
Interactions
Drug: May increase INR with
warfarin; alcohol may cause
disulfiram-like reaction; may increase the half-life of
fosphenytoin, phenytoin; may increase levels and toxicity of
lithium, fluorouracil, cyclosporine, tacrolimus; cholestyramine may decrease absorption of tinidazole;
cimetidine or
ketoconazole may increase levels.
Pharmacokinetics
Peak: 2 h.
Distribution: Crosses bloodbrain barrier and placenta and is excreted in breast milk.
Metabolism: In the liver by CYP3A4.
Elimination: Primarily in urine.
Half-Life: 1214 h.
Nursing Implications
Assessment & Drug Effects
- Withhold drug and notify physician for S&S of CNS dysfunction (e.g., seizures, numbness or paresthesia of extremities).
Drug should be discontinued if abnormal neurological signs appear.
- Lab tests: baseline LTFs; CBC with differential, if retreatment is required.
- Monitor INR/PT frequently with concomitant oral anticoagulants. Continue monitoring for at least 8 d after discontinuation
of tinidazole.
- Monitor serum lithium levels with concurrent use.
- Monitor for phenytoin toxicity with concurrent IV phenytoin.
Patient & Family Education
- Stop taking the drug and report promptly: convulsions, numbness, tingling, pain, or weakness in the hands or feet; dizziness
or unsteadiness; fever.
- Harmless urine discoloration may occur while taking this drug.