Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ACHROMYCIN V vs ACTICLATE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Bacteriostatic; binds reversibly to 30S ribosomal subunit, inhibits protein synthesis by blocking aminoacyl-t RNA binding to 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 bacteria including rickettsiae, Mycoplasma pneumoniae, Chlamydia trachomatis, and spirochetes,Acne vulgaris,Adjunctive therapy in severe acne,Off-label: Chronic prostatitis, sclerosing keratitis, rosacea
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
250-500 mg orally every 6 hours
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.
Terminal elimination half-life is 6-12 hours in patients with normal renal function; prolonged in renal impairment (up to 48-72 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).
Not extensively metabolized; primarily excreted unchanged in urine via glomerular filtration; small amount metabolized in liver.
Primarily hepatic via CYP3A4 and CYP2D6; also undergoes glucuronidation and renal excretion.
Renal (60% unchanged in urine via glomerular filtration), biliary/fecal (40% as active drug and metabolites, with a portion undergoing enterohepatic recirculation).
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.
50-65% bound to serum albumin; primarily binds to alpha-1-acid glycoprotein.
Approximately 75-80% bound primarily to serum albumin and to a lesser extent to alpha-1-acid glycoprotein.
1.5-2.0 L/kg (large volume indicates extensive tissue distribution, concentrating in bile, liver, kidneys, and bone; minimal CNS penetration despite lipophilicity).
Volume of distribution is 1.5-2.5 L/kg, indicating extensive tissue distribution; penetrates well into lung, skin, and soft tissues.
Oral: 60-80% (reduced by food, particularly dairy products, due to chelation with divalent cations). Intravenous: 100%.
Oral bioavailability is approximately 95% with minimal first-pass metabolism; food reduces absorption by 20-30%.
GFR 50-80 m L/min: no adjustment; GFR 10-50 m L/min: 250-500 mg every 12-24 hours; GFR <10 m L/min: 250-500 mg every 24 hours
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).
No dosage adjustment required; use with caution in severe hepatic impairment due to potential hepatotoxicity
Child-Pugh Class A or B: No adjustment; Child-Pugh Class C: Avoid use (insufficient data, potential hepatotoxicity).
Children >8 years: 25-50 mg/kg/day orally divided every 6 hours
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).
Consider age-related renal impairment; adjust dose based on GFR; avoid if possible due to increased risk of photosensitivity and gastrointestinal effects
Use with caution due to increased risk of intracranial hypertension and photosensitivity. Consider renal function; no specific dose adjustment beyond renal dosing.
Use during tooth development (last half of pregnancy, infancy, childhood to age 8 years) may cause permanent discoloration of teeth (yellow-gray-brown).
None.
Photosensitivity manifested by exaggerated sunburn reaction,Renal impairment may lead to drug accumulation and potential hepatotoxicity,Superinfection with resistant organisms including fungi,Bone growth retardation in premature infants,Pseudotumor cerebri (benign intracranial hypertension) in adults
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,Pregnancy,Children under 8 years of age,Severe renal or 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 (milk, cheese, yogurt) and calcium-fortified foods within 2-4 hours of dosing. Also avoid concurrent intake of iron-rich foods or supplements, zinc, magnesium, and antacids. High-fat meals may reduce absorption; take on an empty stomach.
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 ACHROMYCIN V (tetracycline hydrochloride), are classified as FDA Pregnancy Category D. Use during the second and third trimesters may cause permanent tooth discoloration (yellow-gray-brown) and enamel hypoplasia in the fetus. Reversible inhibition of bone growth has been reported. First-trimester exposure is associated with a small risk of neural tube defects and other malformations in some studies. Avoid use during pregnancy unless for serious infections (e.g., anthrax, brucellosis) when alternative antibiotics are contraindicated.
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 in low concentrations. The milk-to-plasma ratio (M/P) is approximately 0.6–0.8. Theoretical risks include dental staining and bone growth inhibition in the nursing infant. Short-term use at recommended doses is generally considered compatible with breastfeeding by the American Academy of Pediatrics, but prolonged or repeated courses should be avoided. Monitor infant for potential gastrointestinal disturbances or rash.
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.
Pregnancy reduces tetracycline serum concentrations due to increased volume of distribution and enhanced hepatic clearance. However, dose adjustments are not routinely recommended because the drug is generally avoided in pregnancy. If use is unavoidable (e.g., anthrax), standard adult doses (e.g., 250-500 mg every 6 hours) may be insufficient; consider monitoring serum levels if available and adjusting based on clinical response. Avoid in the second and third trimesters if possible.
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.
Tetracycline chelates with divalent and trivalent cations; avoid concurrent administration with dairy, antacids, iron, or calcium supplements. Photosensitivity risk: advise sun avoidance and use of sunscreen. Monitor renal function in elderly; adjust dose in severe renal impairment. Not for use in pregnancy or children under 8 years due to tooth discoloration and bone growth inhibition. Administer on an empty stomach (1 hour before or 2 hours after meals) for optimal absorption.
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, at least 1 hour before or 2 hours after meals.,Avoid dairy products, antacids, iron supplements, and calcium supplements within 2-4 hours of taking this drug.,Protect your skin from sun exposure; use sunscreen and wear protective clothing as this medicine can cause severe sunburn.,Do not take this drug if you are pregnant or breastfeeding; it can harm the baby's teeth and bones.,Complete the full course of treatment even if you feel better; do not skip doses.,Report any signs of allergic reaction, severe headache, blurred vision, or persistent diarrhea to your doctor immediately.,Store at room temperature away from moisture and light.
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 ACHROMYCIN V vs ACTICLATE, answered by our medical review team.
ACHROMYCIN V is a Tetracycline Antibiotic that works by Bacteriostatic; binds reversibly to 30S ribosomal subunit, inhibits protein synthesis by blocking aminoacyl-t RNA binding to 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 ACHROMYCIN V 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 ACHROMYCIN V is: 250-500 mg orally every 6 hours. 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 ACHROMYCIN V 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. ACHROMYCIN V is classified as Category C. Tetracyclines, including ACHROMYCIN V (tetracycline hydrochloride), are classified as FDA Pregnancy Category D. Use during the second and third trimesters may cause permanent tooth. 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.