Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
TETRACHEL vs ACTICLATE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Tetracycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, preventing the attachment of aminoacyl-t RNA to the m RNA-ribosome complex.
Inhibits P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), thereby increasing intestinal absorption and decreasing clearance of substrates; also inhibits CYP3A4 isoenzymes, reducing metabolism of CYP3A4 substrates.
Infections caused by susceptible strains of Rickettsiae,Mycoplasma pneumoniae infections,Psittacosis (ornithosis),Chlamydia trachomatis infections (e.g., uncomplicated urethral, endocervical, rectal),Brucellosis (in conjunction with streptomycin),Chancroid,Granuloma inguinale,Lymphogranuloma venereum,Relapsing fever,Bartonellosis,Plague,Tularemia,Acute intestinal amebiasis (adjunctive therapy),Severe acne,Propionibacterium acnes infections,Off-label: Helicobacter pylori eradication (as part of quadruple therapy)
Adjuvant therapy to antibiotics for treatment of refractory infections caused by multidrug-resistant organisms,Off-label: Treatment of hyperuricemia in gout (as a urate-lowering agent when combined with allopurinol),Investigationally: Reversal of P-gp-mediated resistance in certain malignancies
500 mg orally once daily for 28 days; for severe infections, 500 mg twice daily for 14 days.
100 mg orally twice daily (12 hours apart) on an empty stomach (1 hour before or 2 hours after meals). Avoid milk, antacids, iron, calcium, magnesium, and zinc within 2 hours of administration.
6-11 hours (prolonged in renal impairment; up to 57 hours in anuria).
Terminal elimination half-life is approximately 18-22 hours in patients with normal renal function; prolonged to 30-50 hours in moderate renal impairment (Cr Cl 30-50 m L/min).
Tetracycline is primarily metabolized in the liver via glucuronidation and undergoes enterohepatic circulation. Minor metabolism may involve microsomal enzymes.
Primarily hepatic via CYP3A4 and CYP2D6; also undergoes glucuronidation and renal excretion.
Renal 60% (glomerular filtration), fecal 40% (biliary excretion of active drug and metabolites).
Renal excretion of unchanged drug accounts for approximately 60% of the dose; fecal elimination via biliary secretion contributes about 30%; minor metabolism (<10%) produces inactive metabolites.
65% (primarily albumin).
Approximately 75-80% bound primarily to serum albumin and to a lesser extent to alpha-1-acid glycoprotein.
1.3 L/kg (extensive tissue penetration, including bone and teeth).
Volume of distribution is 1.5-2.5 L/kg, indicating extensive tissue distribution; penetrates well into lung, skin, and soft tissues.
Oral: 77-96% (decreased by food, dairy, antacids).
Oral bioavailability is approximately 95% with minimal first-pass metabolism; food reduces absorption by 20-30%.
Cr Cl >50 m L/min: no adjustment. Cr Cl 30-50 m L/min: 250 mg once daily. Cr Cl <30 m L/min: 125 mg once daily.
e GFR 30-60 m L/min/1.73m²: No adjustment needed; e GFR <30 m L/min: Avoid use (contraindicated due to tetracycline accumulation).
Child-Pugh A: no adjustment. Child-Pugh B: 250 mg once daily. Child-Pugh C: 125 mg once daily.
Child-Pugh Class A or B: No adjustment; Child-Pugh Class C: Avoid use (insufficient data, potential hepatotoxicity).
Children ≥8 years: 5 mg/kg orally once daily (max 500 mg) for 28 days.
Weight ≥45 kg and age ≥12 years: 100 mg every 12 hours for 10 days. Weight <45 kg or age <12 years: Not recommended (risk of permanent tooth discoloration and bone growth inhibition).
Initiate at low end of dosing range; monitor renal function and adjust dose based on Cr Cl.
Use with caution due to increased risk of intracranial hypertension and photosensitivity. Consider renal function; no specific dose adjustment beyond renal dosing.
Tetracycline can cause fetal harm when administered to a pregnant woman. Use during tooth development (last half of pregnancy, infancy, and children up to 8 years) may cause permanent discoloration of teeth (yellow-gray-brown). It should not be used in this age group unless other drugs are not likely to be effective or are contraindicated.
None.
Photosensitivity: exaggerated sunburn reaction; avoid direct sunlight and UV light.,Hepatotoxicity: may cause liver damage, especially in patients with renal impairment or receiving high doses.,Renal impairment: accumulation may occur; dosage adjustment required.,Superinfection: use of tetracycline may result in overgrowth of non-susceptible organisms, including fungi.,Pseudomembranous colitis: Clostridium difficile-associated diarrhea has been reported.,Intracranial hypertension: bulging fontanelles in infants and benign intracranial hypertension in adults.,Tissue irritation: avoid extravasation; thrombophlebitis risk with IV administration.
May cause significant drug interactions due to inhibition of P-gp, BCRP, and CYP3A4; monitor for increased toxicity of coadministered drugs (e.g., digoxin, methotrexate, anticancer agents). Use with caution in patients with hepatic impairment.
Hypersensitivity to tetracyclines or any component of the formulation.,Pregnancy (especially second and third trimesters) and lactation.,Children under 8 years of age (except for specific infections like anthrax or where no alternative exists).,Severe hepatic impairment.
Hypersensitivity to active ingredient; concurrent use with narrow therapeutic index drugs that are P-gp or CYP3A4 substrates (e.g., digoxin, colchicine, cyclosporine) unless benefit outweighs risk.
Avoid dairy products, calcium-fortified foods, and antacids containing calcium, magnesium, or aluminum, as they reduce absorption. Iron supplements, bismuth subsalicylate, and zinc also chelate tetracyclines. Take tetracycline 1 hour before or 2 hours after meals. Avoid alcohol (hepatotoxicity risk).
Dairy products (milk, yogurt, cheese), calcium-fortified foods, and high-calcium meals reduce doxycycline absorption. Take doxycycline at least 1-2 hours before or after consuming these foods. Avoid concurrent use with antacids, iron supplements, bismuth subsalicylate, and magnesium-containing laxatives. Alcohol is not known to interact but may increase gastrointestinal irritation.
Tetracyclines, including Tetrachel, are classified as FDA Pregnancy Category D. They can cause fetal harm when administered to a pregnant woman. Use during the second and third trimesters (weeks 13 to 40) is associated with permanent discoloration of teeth (yellow-gray-brown) and enamel hypoplasia in the child. Additionally, there is a risk of retarded skeletal growth and potentially reversible inhibition of bone growth. Use during the first trimester is generally discouraged unless no alternative therapy is available, as there may be a small risk of teratogenicity (e.g., neural tube defects, cardiovascular malformations) based on some observational studies, though evidence is conflicting.
FDA Pregnancy Category D. Tetracyclines, including doxycycline (active ingredient in ACTICLATE), can cause fetal harm when administered to a pregnant woman. Use during tooth development (second and third trimesters) may cause permanent discoloration of teeth (yellow-gray-brown) and enamel hypoplasia. Use during skeletal development may cause reversible inhibition of bone growth. Avoid during pregnancy; alternative therapy should be considered.
Tetracycline is excreted into human milk, with milk-to-plasma ratio (M/P) approximately 0.5-0.8. Low levels of tetracycline are found in breast milk; however, due to potential for serious adverse reactions (e.g., permanent tooth discoloration and bone growth inhibition) in nursing infants, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother. Alternative antibiotics with better safety profiles in lactation are preferred.
Doxycycline is excreted in human milk at low concentrations. The milk-to-plasma ratio is approximately 0.6-0.9. Theoretical risk of dental discoloration and bone growth inhibition in nursing infants exists due to cumulative effects, although absorption by the infant is limited. Caution is advised; consider temporary discontinuation of breastfeeding during treatment or use alternative agent.
Due to physiological changes in pregnancy (increased plasma volume, increased renal clearance), tetracycline may achieve lower serum concentrations. However, specific dosing adjustment guidelines for tetracycline in pregnancy are not established. The drug is generally avoided in pregnancy, particularly after the first trimester. If use is necessary in the first trimester, standard dosing based on non-pregnant adults is typically used, but careful monitoring for efficacy and toxicity is recommended. No dose adjustment is recommended for hepatic or renal impairment in pregnancy as the drug is contraindicated in such conditions.
Doxycycline is contraindicated in pregnancy; no dose adjustment is applicable. If inadvertent exposure occurs in first trimester, no dose adjustment needed, but drug should be discontinued. No pharmacokinetic data suggesting need for dose adjustment if used for life-threatening conditions (e.g., anthrax), but risk-benefit must be carefully assessed.
Tetracyclines are bacteriostatic antibiotics that inhibit protein synthesis. Avoid in children under 8 years and pregnant/breastfeeding women due to bone and tooth discoloration. Administer on an empty stomach (1 hour before or 2 hours after meals) with a full glass of water to prevent esophagitis. Do not take with dairy, antacids, or iron supplements as they chelate and reduce absorption. Photosensitivity risk: advise sun avoidance and sunscreen use.
ACTICLATE (doxycycline hyclate) is a tetracycline antibiotic. Avoid concomitant use with antacids, dairy products, or iron supplements as they chelate doxycycline, reducing absorption. Administer with a full glass of water and avoid lying down for 30 minutes to reduce esophageal irritation. Photosensitivity is common; advise sun avoidance and sunscreen use. Do not use in children <8 years or during pregnancy/lactation due to tooth discoloration and bone growth inhibition. Monitor for pseudomembranous colitis and superinfection.
Take this medication on an empty stomach with a full glass of water.,Avoid dairy products, antacids, and iron supplements within 2 hours of taking this drug.,Use sunscreen and protective clothing to prevent severe sunburn.,Complete the full course of therapy even if you feel better.,Report any signs of allergic reaction, severe headache, or vision changes immediately.
Take doxycycline exactly as prescribed. Do not skip doses or stop early even if you feel better.,Take with a full glass of water. Avoid lying down for at least 30 minutes after taking to prevent esophageal irritation.,Avoid taking with milk, yogurt, cheese, or calcium-fortified foods. Also avoid antacids, iron, and bismuth subsalicylate within 2 hours of doxycycline.,Use sunscreen and protective clothing; doxycycline increases sensitivity to sunlight and can cause severe sunburn.,If you miss a dose, take it as soon as you remember unless it is near the time of the next dose. Do not double the dose.,Report persistent diarrhea, severe headache, vision changes, or allergic reactions (rash, swelling) to your healthcare provider immediately.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about TETRACHEL vs ACTICLATE, answered by our medical review team.
TETRACHEL is a Tetracycline Antibiotic that works by Tetracycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, preventing the attachment of aminoacyl-t RNA to the m RNA-ribosome complex.. ACTICLATE is a Tetracycline Antibiotic that works by Inhibits P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), thereby increasing intestinal absorption and decreasing clearance of substrates; also inhibits CYP3A4 isoenzymes, reducing metabolism of CYP3A4 substrates.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between TETRACHEL and ACTICLATE depend on the specific clinical indication. These are both Tetracycline Antibiotic agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of TETRACHEL is: 500 mg orally once daily for 28 days; for severe infections, 500 mg twice daily for 14 days.. The standard adult dose of ACTICLATE is: 100 mg orally twice daily (12 hours apart) on an empty stomach (1 hour before or 2 hours after meals). Avoid milk, antacids, iron, calcium, magnesium, and zinc within 2 hours of administration.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between TETRACHEL and ACTICLATE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. TETRACHEL is classified as Category C. Tetracyclines, including Tetrachel, are classified as FDA Pregnancy Category D. They can cause fetal harm when administered to a pregnant woman. Use during the second and third tri. ACTICLATE is classified as Category C. FDA Pregnancy Category D. Tetracyclines, including doxycycline (active ingredient in ACTICLATE), can cause fetal harm when administered to a pregnant woman. Use during tooth develo. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.