Dynacin Uses, Dosage, Side Effects, Food Interaction and all others data.

Trade Name Dynacin
Availability Prescription only
Generic Minocycline
Minocycline Other Names Minociclina, Minociclinum, Minocyclin, Minocycline, Minocyclinum, Minomycin
Related Drugs amoxicillin, prednisone, doxycycline, ciprofloxacin, cephalexin, metronidazole, azithromycin, clindamycin topical, ceftriaxone, dexamethasone
Type Capsules
Formula C23H27N3O7
Weight Average: 457.4764
Monoisotopic: 457.184900233
Protein binding

Minocycline is 76% protein bound in serum.

Groups Approved, Investigational
Therapeutic Class Tetracycline group of drugs
Available Country United States,
Last Updated: September 19, 2023 at 7:00 am


Dynacin is used for oral administration, for the treatment of infections caused by tetracycline sensitive organisms and some tetracycline resistant strains of staphylococci. Indications include: Acne, skin and soft tissue infections, ophthamological infections, acute and chronic bronchitis, bronchiectasis, lung abscess, ear, nose and throat infections, pelvic inflammatory disease, nocardiosis, urinary tract infections, gonorrhoea, non-gonococcal urethritis and prostatitis. Dynacin may also be used in prophylactic treatment of asymptomatic meningococcal carriers. Also used for pre- and post-operative prophylaxis of infection.
Renal impairment: As adults even in cases of mild to moderate renal impairment. However, caution is advised in patients with severe renal impairment.
Paediatric population: Dynacin is not recommended in children under 12 years. Children over 12 years: 50mg every 12 hours.

Dynacin is also used to associated treatment for these conditions: Bartonellosis, Brucellosis, Campylobacter fetus, Chancroid, Cholera, Conjunctivitis, Inclusion, Granuloma Inguinale, Lymphogranuloma Venereum, Nongonococcal urethritis, Periodontitis, Plague, Psittacosis, Q Fever, Relapsing Fever, Respiratory Tract Infections (RTI), Rickettsia Infections, Rickettsialpox, Rocky Mountain Spotted Fever, Trachoma, Tularemia, Typhus Fever, Inflammatory lesions

How Dynacin works

Tetracyclines enter bacterial cells through OmpF and OmpC porins by coordinating with cations like magnesium. This allows tetracyclines into the periplasm where they dissociate, allowing the lipophilic tetracycline to diffuse into the bacterial cytoplasm. Tetracyclines prevent aminoacyl-tRNA from binding to the 30S ribosome, inhibiting protein synthesis.


Dynacin dosage

  • Routine antibiotic use: 200 mg daily in divided doses
  • Acne: 50 mg twice daily for at least 6 weeks.
  • Gonorrhoea: Males: 200 mg initially followed by 100 mg every 12 hours for a minimum of 4 days. Post therapy cultures within 2-3 days. Females: May require a more prolonged therapy.
  • Prophylaxis of asymptomatic meningococcal carriers: 100 mg twice daily for 5 days, followed by treatment with rifampicin.
If, after six months, there is no satisfactory response minocycline should be discontinued and other therapies considered. If minocycline is to be continued for longer than six months, patients should be monitored at least three monthly intervals thereafter for signs and symptoms of hepatitis or SLE.

Side Effects

Reported side effects are oral and anogenital candidiasis, vulvovaginitis, eosinophilia, leucopenia, neutropenia, thrombocytopenia, haemolytic anaemia, pancytopenia, agranulocytosis, anaphylaxis, anaphylactoid reaction, hypersensitivity, pulmonary infiltrates, anaphylactoid purpura, polyarthritisnodosa, abnormal thyroid function, brown-black discolouration of the thyroid, anorexia, dizziness, headache, hypaesthesia, paraesthesia, intracranial hypertension, vertigo, Bulging fontanelle, convulsions, sedation, impaired hearing, tinnitus, myocarditis, pericarditis, cough, dyspnoea, bronchospasm, exacerbation of asthma, pulmonary eosinophilia, pneumonitis, diarrhoea, nausea, stomatitis, discolouration of teeth, vomiting, dyspepsia, dysphagia, enamel hypoplasia, enterocolitis, oesophagitis, oesophageal ulceration, glossitis, pancreatitis, pseudomembranous colitis, increased liver enzymes, hepatitis, autoimmune hepatotoxicity, hepatic cholestatis, hepatic failure, hyperbilirubinemia, jaundice, autoimmune hepatitis, alopecia, erythema multiforme, erythema nodosum, fixed drug eruption, hyperpigmentation of the skin, photosensitivity, pruritis, rash, urticaria, vasculitis, angioedema, exfoliative dermatitis, hyperpigmentation of nails, Stevens-Johnson syndrome, toxic epidermal necrolysis, Drug reaction with eosinophilia and systemic symptoms (DRESS), arthralgia, lupus-like syndrome, myalgia, arthritis, bone discolouration, cases of systemic lupus erythematous (SLE), joint stiffness, joint swelling, increased serum urea, acute renal failure, interstitial nephritis, balanitis, fever, etc. In some cases involving these syndromes, death has been reported.

Hyperpigmentation of various body sites including the skin, nails, teeth, oral mucosa, bones, thyroid, eyes (including sclera and conjunctiva), breast milk, lacrimal secretions and perspiration has been reported. This blue/black/grey or muddy-brown discolouration may be localised or diffuse. The most frequently reported site is in the skin. Pigmentation is often reversible on discontinuation of the drug, although it may take several months or may persist in some cases. The generalised muddy-brown skin pigmentation may persist, particularly in areas exposed to the sun.


The oral LD50 in rats is 2380mg/kg and in mice is 3600mg/kg. The intraperitoneal LD50 in rats is 331mg/kg and in mice is 299mg/kg. The subcutaneous LD50 in rats is 1700mg/kg and in mice is 2290mg/kg.

Patients experiencing an overdose may present with dizziness, nausea, and vomiting. In the event of an overdose, discontinue minocycline and treat patients with symptomatic and supportive measures.


Breathing difficulties: Cases of breathing difficulties including dyspnoea, bronchospasm, exacerbation of asthma, pulmonary eosinophilia and pneumonitis have been reported with minocycline use. If patients develop breathing difficulties they should seek urgent medical advice and minocycline should be discontinued.

Paediatric population: All tetracyclines form a stable calcium complex in any bone forming tissue. An increase in the fibula growth rate has been observed in premature babies administered oral tetracyclines. Tetracyclines are known to cause a yellow to brown discoloration of the teeth and enamel hypoplasia in the developing child or foetus.

Hepatic impairment: Dynacin should be used with caution in patients with hepatic dysfunction or in conjunction with potentially hepatotoxic drugs, including alcohol.

Auto-immune disorders: Rare cases of auto-immune hepatotoxicity and isolated cases of systemic lupus erythematosus (SLE) have been reported. If patients develop signs or symptoms of SLE or hepatotoxicity, minocycline should be discontinued.

Renal impairment: Studies indicate there is no significant drug accumulation in patients with mild to moderate renal impairment when treated with the recommended dosages of minocycline. In cases of severe renal impairment a reduction of dosage and monitoring of renal function may be required.

Cross-sensitivities: Micro-organisms can develop cross resistance to tetracyclines and patients can develop cross sensitivity. Dynacin should be discontinued there are signs/symptoms of overgrowth of resistant organisms.

Intracranial hypertension: As with other tetracyclines, bulging fontanelles in infants and benign intracranial hypertension in juveniles and adults have been reported. Presenting features were headache and visual disturbances including blurring of vision, scotoma and diplopia. Permanent vision loss has been reported. Treatment should cease if evidence of raised intracranial pressure develops.

Hyperpigmentation: As with other tetracyclines, minocycline may cause hyperpigmentation at various body sites. Hyperpigmentation may present regardless of dose or duration of therapy but develops more commonly during long term treatment. Patients should be advised to report any unusual pigmentation without delay and minocycline should be discontinued.

Photosensitivity: Tetracyclines are known to cause photosensitivity reactions. Such patients should be warned to avoid direct exposure to natural or artificial sunlight and to discontinue therapy at the first sign of skin discomfort.


Anticoagulants: Plasma prothrombin activity is depressed by tetracyclines. Reduced doses of any concomitant anticoagulants may be necessary.
ACE inhibitors, antacids and adsorbants: Tetracyclines bind to di-/tri-valent cations. Absorption from the gastrointestinal tract is impaired by the concomitant administration of iron, calcium, aluminium, magnesium, bismuth and zinc salt (interactions with specified salts, antacids, kaolin, bismuth containing ulcer-healing drugs, quinapril which contains a magnesium carbonate excipient). Dosages should be maximally separated. Absorption of tetracyclines is not significantly impaired by food, milk and milk products.
Diuretics: Diuretics may aggravate nephrotoxicity by volume depletion.
Antibacterials: Dynacin should not be used with penicillins.
Ergotamine and ergometrine: There is an increased risk of ergotism.
Oral contraceptives: Both can induce hyperpigmentation.
Retinoids: Administration of isotretinoin should be avoided shortly before, during and shortly after minocycline therapy.

Food Interaction

  • Avoid multivalent ions. Separate administration of aluminium, calcium, iron and magnesium containing products from medication by at least 2 hours.
  • Take with or without food.

Dynacin multivitamins interaction

[Moderate] GENERALLY AVOID: The bioavailability of oral tetracyclines and iron salts may be significantly decreased during concurrent administration.

Therapeutic failure may result.

The proposed mechanism is chelation of tetracyclines by the iron cation, forming an insoluble complex that is poorly absorbed from the gastrointestinal tract.

In ten healthy volunteers, simultaneous oral administration of ferrous sulfate 200 mg and single doses of various tetracyclines (200 mg to 500 mg) resulted in reductions in the serum levels of methacycline and doxycycline by 80% to 90%, oxytetracycline by 50% to 60%, and tetracycline by 40% to 50%.

In another study, 300 mg of ferrous sulfate reduced the absorption of tetracycline by 81% and that of minocycline by 77%.

Conversely, the absorption of iron has been shown to be decreased by up to 78% in healthy subjects and up to 65% in patients with iron depletion when ferrous sulfate 250 mg was administered with tetracycline 500 mg.

Available data suggest that administration of iron 3 hours before or 2 hours after a tetracycline largely prevents the interaction with most tetracyclines except doxycycline.

Due to extensive enterohepatic cycling, iron binding may occur with doxycycline even when it is given parenterally.

It has also been shown that when iron is administered up to 11 hours after doxycycline, serum concentrations of doxycycline may still be reduced by 20% to 45%.

Coadministration of a tetracycline with any iron-containing product should be avoided if possible.

Otherwise, patients should be advised to stagger the times of administration by at least three to four hours, although separating the doses may not prevent the interaction with doxycycline.

Volume of Distribution

The volume of distribution of minocycline has been reported as 67.5-115L.

Elimination Route

100mg of oral minocycline reaches a Cmax of 1.6mg/L, with a Tmax of 1.9h, and an AUC of 31.6mg/L*h. 200mg of oral minocycline reaches a Cmax of 3.1mg/L, with a Tmax of 2.5h, and an AUC of 48.3mg/L*h.

Half Life

The half life of minocycline pellet filled capsules is 11.1-22.1 hours. Dynacin intravenous injections have a half live of 15-23 hours.


Intravenous minocycline has a clearance of 3.36-5.7L/h, while oral minocycline has a clearance of 3.42-4.4L/h.

Elimination Route

Dynacin is predominantly eliminated through the biliary route. 4.5-9% of an intravenous minocycline dose is recovered in the urine. 10-19.5% of an oral dose is recovered in the urine and 20-34% is recovered in the feces.

Pregnancy & Breastfeeding use

Dynacin use during pregnancy and lactation is contraindicated. Animal studies have indicated that tetracyclines cross the placenta. Tetracyclines have been found in foetal tissues and can have toxic effects on the developing foetus (related to retardation of skeletal development). Studies on animals treated during early pregnancy also indicate embryotoxicity. The use of tetracyclines during the last half of pregnancy, when the teeth are developing, may cause permanent discolouration of teeth (more common with long term or repeated short term use). Enamel hypoplasia has also been reported. Tetracyclines have been detected in the milk of lactating women. Permanent tooth discolouration may occur in the developing infant and enamel hypoplasia has been reported.


Dynacin is contraindicated in patients with hypersensitivity to tetracyclines, systemic lupus erythematosus, pregnancy, lactation, complete renal failure and children under 12 years.

Acute Overdose

Dizziness, nausea and vomiting are the adverse effects most commonly seen in overdose. Gastric lavage plus appropriate supportive treatment. Antacids and calcium salts will reduce absorption of minocycline but there is no specific antidote. Dynacin is not removed in significant quantities by haemodialysis or peritoneal dialysis.

Storage Condition

Store in a cool and dry place, protected from light, store below 25°C.

Innovators Monograph

You find simplified version here Dynacin

Dynacin contains Minocycline see full prescribing information from innovator Dynacin Monograph, Dynacin MSDS, Dynacin FDA label


What is Dynacin used for?

Dynacin capsules are used to treat bacterial infections in many different parts of the body. It is also used to treat anthrax infection and other infections in patients who cannot receive penicillins.

How safe is Dynacin?

Overall, Dynacin is safer than ibuprofen or penicillin. Dynacin has been a standard treatment for severe acne for over 20 years and has been proven safe and effective with proper usage. Dynacin is safe, long-term, for acne, when such doses are clinically necessary.

How does Dynacin work?

Dynacin works to treat infections by preventing the growth and spread of bacteria. It works to treat acne by killing the bacteria that infects pores and decreasing a certain natural oily substance that causes acne.

What are the common side effects of Dynacin?

Common side effects of Dynacin are Nausea, vomiting, diarrhea, lightheadedness, dizziness, or a feeling of spinning may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Is Dynacin safe during pregnancy?

No, Dynacin is not safe to take during pregnanacy.

Is Dynacin safe during breastfeeding?

Short-term use of Dynacin is acceptable in nursing mothers. As a theoretical precaution, avoid prolonged or repeat courses during nursing. Monitor the infant for rash and for possible effects on the gastrointestinal flora, such as diarrhea or candidiasis (thrush, diaper rash).

Can I drink alcohol with Dynacin?

Liver toxicity is a rare side effect of taking Dynacin. Since alcohol can also have negative effects on the liver, people should avoid mixing alcohol with Dynacin.

Can I drive after taking Dynacin?

You should be cautious with regard to driving a car or operating heavy machinery if your doctor gives you a prescription for minocycline. Lightheadedness and dizziness are potential side effects if you take this medication.

Can Dynacin be taken on an empty stomach?

The extended-release tablet is usually taken once a day to treat acne. Dynacin can be taken with or without food.

Should I take Dynacin in the morning or night?

Start off taking it only at bedtime for a few days until ones body gets "used to" this medication. During this time dizziness or headaches may occur. These last a few hours and are gone by the morning. After that, the medication can be taken any time and is easiest to remember at meals.

How many time can I take Dynacin daily?

The capsule and pellet-filled capsule is usually taken twice a day (every 12 hours) or four times a day (every 6 hours).

How long can I take Dynacin?

Oral antibiotics can take about six to eight weeks to start working, so you won't see results right away. Even if you aren't seeing any improvement, it's important to keep taking Dynacin as directed by your doctor.

How long does Dynacin stay in my system?

It usually takes around 5.5 x elimination half-life (hours) before a drug is completely cleared from your system. So if we take the maximum elimination half life of 22 hours, it would take 121 hours (5.5 x 22 hours) approximately 5 days before the medicine is eliminated from your system.

Can I take Dynacin for a long time?

Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects. This medicine is not for long-term use.

How long can I stay on Dynacin?

The bacteria learn how to survive antibiotic treatment, making them especially hard to kill. To avoid this, your doctor will likely prescribe Dynacin for at least three months. If your acne improves before then, they might reduce your dose or switch you over to a topical antibiotic.

What happen If I stop taking Dynacin?

It usually goes away after Dynacin is stopped; however, there is a chance of permanent vision loss or blindness. Get medical help right away if you have: severe/lasting headache, vision changes (such as blurred/double vision, decreased vision, sudden blindness), nausea/vomiting that doesn't stop.

What happens if I miss a dose?

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

What happens if I overdose?

Seek emergency medical attention. Overdose symptoms may include dizziness, nausea, or vomiting.

Who should not take Dynacin?

You should not take this medicine if you are allergic to Dynacin or to similar antibiotics such as demeclocycline, doxycycline, or tetracycline. If you are using Dynacin to treat gonorrhea, your doctor may test you to make sure you do not also have syphilis, another sexually transmitted disease. To make sure this medicine is safe for you, tell your doctor if you have ever had: liver disease; kidney disease; or asthma or sulfite allergy.

Can Dynacin cause heart problems?

However, elderly patients are more likely to have kidney, liver, or heart problems, which may require caution and an adjustment in the dose for patients receiving Dynacin.

Does Dynacin cause anxiety?

On the other hand, Dynacin is also an antibiotic, and antibiotic treatments have been shown to increase the risk for depression and anxiety.

Can Dynacin affects my liver?

Dynacin therapy is associated with two forms of clinically apparent liver injury, an acute hepatitis-like syndrome that arises within 1 to 3 months of starting therapy and a chronic hepatitis-like syndrome typically with autoimmune features that occurs with long term therapy, sometimes after several years of use.

Can Dynacin affect my kidneys?

Using expired Dynacin can cause damage to your kidneys.

Will Dynacin affect my fertility?

Dynacin have been shown to be toxic to sperm at any concentration.

*** Taking medicines without doctor's advice can cause long-term problems.