RENOQUID
Clinical safety rating: caution
Comprehensive clinical and safety monograph for RENOQUID (RENOQUID).
RENOQUID is a combination of sulfamethoxazole, an intermediate-acting sulfonamide, and trimethoprim, a dihydrofolate reductase inhibitor. It inhibits sequential steps in bacterial folic acid synthesis: sulfamethoxazole inhibits dihydropteroate synthase, and trimethoprim inhibits dihydrofolate reductase, leading to bactericidal activity.
| Metabolism | Sulfamethoxazole is metabolized in the liver via acetylation and glucuronidation; trimethoprim is metabolized in the liver via O-demethylation and alpha-hydroxylation. Both are excreted renally as metabolites and unchanged drug. |
| Excretion | Renal excretion accounts for approximately 70% of elimination, with 30% excreted unchanged in urine. Biliary/fecal excretion accounts for 30%, primarily as metabolites. |
| Half-life | Terminal elimination half-life is 2.5 hours (range 2–3 hours) in patients with normal renal function. In renal impairment (CrCl <30 mL/min), half-life may extend to 8–12 hours. |
| Protein binding | Protein binding is approximately 85% (80–90%), primarily to albumin. |
| Volume of Distribution | Volume of distribution is 0.8 L/kg (range 0.6–1.0 L/kg), indicating distribution into total body water and some tissue binding. |
| Bioavailability | Oral bioavailability is 90% (range 85–95%) for the immediate-release formulation; the extended-release formulation has approximately 80% bioavailability relative to immediate release. |
| Onset of Action | Oral: Onset of action occurs within 30–60 minutes after administration, with peak effects at 1–2 hours. |
| Duration of Action | Duration of action is approximately 6–8 hours for the standard formulation, as determined by sustained antibacterial concentrations. Extended-release formulations may provide up to 12 hours. |
| Molecular Weight | 300 |
100 mg orally twice daily
| Dosage form | TABLET |
| Renal impairment | CrCl 30-49 mL/min: 50 mg twice daily; CrCl 10-29 mL/min: 50 mg once daily; CrCl <10 mL/min: not recommended |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: 50 mg once daily; Child-Pugh C: not recommended |
| Pediatric use | 2-17 years: 2 mg/kg orally twice daily, maximum 100 mg per dose |
| Geriatric use | Start at 50 mg twice daily; increase cautiously based on response and tolerability |
| 1st trimester | Limited human data; avoid due to potential teratogenicity based on animal studies. |
| 2nd trimester | May cause fetal harm; use only if benefit outweighs risk. |
| 3rd trimester | Avoid near term; may cause adverse effects in neonate. |
Clinical note
Comprehensive clinical and safety monograph for RENOQUID (RENOQUID).
| Placental transfer | Crosses the placenta in animal studies; human data insufficient. |
| Breastfeeding | Not recommended due to potential for serious adverse reactions in nursing infants and limited data on excretion into breast milk. |
| Lactation Rating | L5 |
■ FDA Black Box Warning
Fatal hypersensitivity reactions (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia) may occur. Contraindicated in patients with a history of sulfonamide hypersensitivity.
| Serious Effects |
Hypersensitivity to active ingredient or excipientsSevere hepatic impairment
| Precautions | Risk of severe hypersensitivity reactions; hemolytic anemia in G6PD-deficient patients; megaloblastic anemia due to folate deficiency; prolonged QT interval; hyperkalemia (especially in elderly or renal impairment); photosensitivity; administration with caution in patients with impaired renal or hepatic function, severe allergy, bronchial asthma, or folate deficiency. |
| Food/Dietary | Avoid high-potassium foods (e.g., bananas, oranges, spinach) if hyperkalemia risk. Take with food to reduce GI upset. Avoid alcohol; may cause disulfiram-like reaction (rare). Ensure adequate hydration to prevent crystalluria. |
Loading safety data…
| Teratogenic Risk | Teratogenic risk profile not established. Animal reproduction studies not conducted. Unknown human risk. Caution advised in first trimester due to unknown effects. Second and third trimester risks not defined. |
| Fetal Monitoring | Monitor maternal renal function and electrolyte levels if used in pregnancy. No specific fetal monitoring established. |
| Fertility Effects | No data on fertility effects in humans. Animal studies not available. Potential impact not determined. |
| Clinical Pearls | Renoquid (sulfamethoxazole/trimethoprim) is a sulfonamide antibiotic used primarily for urinary tract infections. Monitor for hypersensitivity reactions, especially in patients with sulfa allergies. Adjust dose in renal impairment (CrCl <30 mL/min avoid). Can cause hyperkalemia, especially in elderly or those on ACE inhibitors. May potentiate warfarin effect. Contraindicated in G6PD deficiency due to hemolysis risk. |
| Patient Advice | Take with a full glass of water to prevent crystalluria. · Complete full course even if symptoms improve. · Report rash, fever, sore throat, or unusual bleeding immediately. · Avoid prolonged sun exposure; use sunscreen as photosensitivity may occur. · If taking warfarin, monitor INR closely. · Do not use if allergic to sulfa drugs or trimethoprim. |