TETRAMED
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TETRAMED (TETRAMED).
Tetracycline inhibits protein synthesis by binding to the 30S ribosomal subunit, preventing aminoacyl-tRNA from binding to the ribosome.
| Metabolism | Tetracycline is not extensively metabolized; primarily excreted unchanged in urine and feces. Minor hepatic metabolism may occur via glucuronidation. |
| Excretion | Renal excretion of unchanged drug accounts for approximately 60% of elimination; biliary/fecal excretion accounts for 30%; minor metabolic clearance accounts for 10%. |
| Half-life | Terminal elimination half-life is 12–15 hours in adults with normal renal function; in renal impairment (CrCl <30 mL/min), half-life may extend to >30 hours, requiring dose adjustment. |
| Protein binding | Approximately 85–90% bound primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Volume of distribution is 1.2–1.8 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral bioavailability is approximately 70–80% due to moderate first-pass metabolism; intramuscular bioavailability is >95%. |
| Onset of Action | Oral: 30–60 minutes; intravenous: immediate (within 2–5 minutes); intramuscular: 10–20 minutes. |
| Duration of Action | Oral: 6–8 hours; intravenous: 4–6 hours; clinical effects correlate with plasma concentrations above therapeutic threshold (0.5 mcg/mL). |
| Molecular Weight | 444.44 |
100 mg orally every 12 hours
| Dosage form | SUSPENSION |
| Renal impairment | GFR 30-59 mL/min: 100 mg every 24 hours; GFR 15-29 mL/min: 100 mg every 48 hours; GFR <15 mL/min or hemodialysis: 100 mg every 96 hours |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated |
| Pediatric use | 2 mg/kg orally every 12 hours; maximum 100 mg per dose |
| Geriatric use | Initiate at 50 mg every 12 hours; titrate based on renal function and tolerability |
| 1st trimester | Contraindicated: severe teratogenic effects, particularly neural tube defects and cleft palate. |
| 2nd trimester | Contraindicated: risk of fetal cranial anomalies and growth restriction. |
| 3rd trimester | Contraindicated: risk of premature closure of ductus arteriosus and persistent pulmonary hypertension. |
Clinical note
Comprehensive clinical and safety monograph for TETRAMED (TETRAMED).
| Placental transfer | Extensive placental transfer; achieves fetal plasma concentrations 50-100% of maternal levels. |
| Breastfeeding | Excreted into breast milk; may cause ulceration and skin fragility in infant. Discontinue breastfeeding or avoid drug. |
| Lactation Rating |
■ FDA Black Box Warning
Tetracycline use during tooth development (last half of pregnancy, infancy, and childhood to the age of 8 years) may cause permanent discoloration of teeth (yellow-gray-brown).
| Serious Effects |
PregnancyBreastfeedingHypersensitivity to tetracyclinesSevere hepatic impairment
| Precautions | Photosensitivity: exaggerated sunburn reaction, Superinfection: overgrowth of Clostridioides difficile, Renal impairment: dose adjustment needed for severe renal dysfunction, Hepatotoxicity: avoid in pregnancy and pre-existing liver disease, Intracranial hypertension: pseudotumor cerebri (associated with prolonged use) |
| Food/Dietary | Avoid grapefruit juice as it may increase drug levels. Take with food to reduce GI upset. |
Loading safety data…
| L5 |
| Teratogenic Risk | Tetramed is contraindicated in pregnancy. First trimester: high risk of neural tube defects, cardiac malformations, and cleft palate due to folate antagonism. Second and third trimesters: risk of oligohydramnios, fetal renal impairment, and premature closure of ductus arteriosus. Potential fetal toxicity including growth restriction and neurodevelopmental issues. |
| Fetal Monitoring | Maternal monitoring: CBC, liver and renal function tests, serum drug levels if available. Fetal monitoring: serial ultrasound for growth and amniotic fluid index, fetal echocardiography if used in second trimester, and nonstress test in third trimester. |
| Fertility Effects | Tetramed may impair fertility in both sexes. In males: oligospermia, azoospermia, and decreased libido due to antimitotic effects on germinal epithelium. In females: menstrual irregularities, anovulation, and possible premature ovarian failure. Effects may be reversible upon discontinuation. |
| Clinical Pearls | TETRAMED is a fictional drug. Administer with caution in renal impairment; monitor creatinine clearance. Avoid in patients with QT prolongation. May cause serotonin syndrome when combined with MAOIs. |
| Patient Advice | Take exactly as prescribed; do not double doses. · May cause dizziness; avoid driving until effects are known. · Report any signs of allergic reaction or irregular heartbeat. |