Even some 100 years ago, people died from diseases such as meningitis, pneumonia, and many other infectious diseases. Their death was due to the lack of any antimicrobial drugs. Nowadays, we have hundreds of antibiotics, which are special substances that inhibit the reproduction of bacteria and cause their death. Tetracycline is one of them.

If you have bronchitis, pneumonia, purulent pleurisy, subacute septic endocarditis, bacterial and amoebic dysentery, whooping cough, tonsillitis, scarlet fever, gonorrhea, brucellosis, tularemia, typhus and reverse typhus, psittacosis, ornithosis, urinary infections and biliary tract, purulent meningitis, skin infections, or cholera, your doctor might prescribe this medication.

Tetracycline ointment is prescribed for external use, including acne and bacterial skin infections. There is also ointment made specifically for treating bacterial eye infections – blepharitis, keratitis, keratoconjunctivitis, meibomitis, trachoma, and eye damage with rosacea.

Pricing in US and Canadian pharmacies

Tetracycline is a generic version of a brand-name drug that is sold under different names. For 100 pills with a 500 mg dosage, you will pay around $45 in Canada. In the United States, the pricing policy varies greatly and you can find 100 pills with a 500 mg dosage for about $130 or pay as much as $400. Although these prices do not look very affordable if you compare them to the brand-name products you will realize that you are paying only a fraction of the price.

As you can see, the price difference for the same medication is huge. Even if you find the best deal in the United States, it will be about three times more expensive than in Canada. In many cases, it is cheaper to purchase from Canada and get shipped from across the border.

Dosages of Tetracycline

For adults, the dosage is from 0.3 g to 0.5 g 4 times a day or from 0.5 g to 1 g 2 times a day. The maximum daily dose is 4 g. The course of treatment is 5-10 days.

Children over 12 years old need to take  6.25-12.5 mg/kg every 6 hours or 12.5-25 mg/kg every 12 hours. Adequate and strictly controlled studies in children under 12 years of age have not been conducted. Thus, your doctor should determine if it is reasonable to give this medication to a child and at what dose.

The dosages also vary based on the disease one is treating. The most common include:

  • The daily dose is 0.5–2 g, which is divided into couple intakes throughout the day. If the condition improves, the dose is gradually reduced to a maintenance dose of 0.1-1 g.
  • A dose of 0.5 g every 6 hours is taken for 3 weeks simultaneously in combination with other medications.
  • Uncomplicated gonorrhea, syphilis, and chlamydia. The initial single dose is 1.5 g, then 0.5 g every 6 hours for 4 days to 15 days.
  • Lyme disease (early stage only). One takes 1.0-1.5 g per day for 10-14 days.
  • A dose of 0.2-0.3 g is recommended every 6 hours for 7-10 days.
  • One should take 3 g per day for the first 10 days, then 0.5 g every 6 hours for the next 18 days.
  • A dose of 1.5-2 g per day is prescribed for 10 days or 15-20 days for chronic, complicated forms.
  • A dose of 0.5 g is used every 6 hours (weakening and disappearance of the symptoms of the disease occur after 24-48 hours). Treatment is continued for 7-14 days after normalization of body temperature to prevent relapse.
  • Vesicular rickettsiosis. A recommended dose is 0.8–1.2 g per day for 8–10 days.
  • One should take 1.5-2 g per day. After normalization of temperature, treatment is continued for another 5-7 days.
  • The dosage is up to 6 g per day. The dose goes down to 2 g per day after the symptoms get better and is used for at least three days until the temperature normalizes. Contact persons should take a course of 0.3 g every 6 hours.

Elderly individuals do not need to adjust the amount and can just take the typical adult dose. The drug should be used with caution if one has renal failure, though, as this can lead to a cumulation of the drug and overdose.

In general, the use of tetracycline is contraindicated to individuals with renal insufficiency, unless the use of this class of antibiotics is considered absolutely necessary. The daily dose must be reduced and/ or the intervals between doses should be lengthened.

How to use

Tetracycline should not be taken with meals, as foods and some dairy products reduce absorption. Thus, it is recommended to wait at least two hours after you ate or take it one hour ahead of your meal. Tablets should be swallowed in an upright position, sitting or standing, long before bedtime, with plenty of water.

This drug should not be combined with milk and other dairy products because calcium in them hinders absorption. It happens because this substance forms hardly soluble complexes with calcium, iron, and other metal ions. It should also not be combined with antacids containing salts of aluminum, calcium, or magnesium, as well as with iron supplements.

For adults and children over 12 years of age, a single dose is 200 mg every 6 hours. In severe cases, it may be increased up to 500 mg. Most infections require a treatment of at least 5 days and it can be as long as one month.

If using Tetracycline ointment, the affected area of the skin is treated several times a day. If necessary the treated area can be protected with a bandage. This medication can also be used for the eyes and the medical specialist will explain the whole process in detail.

Although the recommended dosages were given here for informational purposes, it is the doctor who ultimately determines the dosage, frequency of intake, and duration individually depending on the nature and severity of the disease. Treatment should be continued for another 3 days after the disappearance of the symptoms.

Side effects

The digestive system is the first one to suffer from the intake of antibiotics. You might get away with relatively mild symptoms such as loss of appetite and nausea or experience more unpleasant ones such as vomiting and diarrhea. In the worst-case scenario, you might get glossitis, esophagitis, gastritis, ulceration of the stomach and duodenum, dysphagia, hepatotoxic effect, pancreatitis, intestinal dysbacteriosis, enterocolitis, increased activity of “liver” transaminases.

The nervous system is also affected by this drug, so you might get a headache, but in very rare cases, the intake can lead to a rise in the pressure inside the skull, which is very risky, or toxic effect on the central nervous system (dizziness or unsteadiness). Hemolytic anemia, thrombocytopenia, neutropenia, and eosinophilia are the other possible side effects.

Azotemia, hyperproteinemia, and nephrotoxic effects are the adverse effects that one might face when it comes to the urinary system. Other side effects can include superinfection, candidiasis, hypovitaminosis of B vitamins, discoloration of tooth enamel in younger individuals, and stomatitis.

Allergic reactions can show up as a maculopapular rash, skin hyperemia, angioedema, anaphylactoid reactions, drug-induced systemic lupus erythematosus, and photosensitivity. When it comes to the ointment the allergic reactions would include burning, flushing of the skin, swelling, or other signs of irritation.

Contraindications and precautions of Tetracycline

Hypersensitivity to any of the components, renal failure, and leukopenia are instant contraindications for tetracycline. One should be careful when using Tetracycline if they have liver dysfunction.

In children, this drug can cause long-term discoloration of the teeth and enamel hypoplasia, slowing down the longitudinal growth of the bones of the skeleton. Thus, it is also not prescribed to kids.

It is contraindicated during pregnancy because Tetracycline passes through the placenta, and accumulates in the bones and tooth germs of the fetus, disrupting their mineralization. This can cause severe impairment of bone tissue development.

At the time of treatment, it is necessary to stop breastfeeding. Tetracyclines penetrate breast milk and can adversely affect the bones and teeth of a child who is in an active stage of growth, as well as cause photosensitivity reactions, and candidiasis of the oral cavity and vagina in infants.

The Tetracycline ointment is not recommended for deep or stab wounds or severe burns. It should be borne in mind that the use of antibacterial agents for external use can lead to sensitization of the body, accompanied by the development of hypersensitivity reactions. If the condition does not improve within 2 weeks, further medical examination and consultation are required.

With prolonged use, it is necessary to periodically monitor the functions of the kidneys, liver, and hematopoietic organs. Vitamins of groups B, K, and yeast should be used for the prevention of hypovitaminosis during the period one is using this drug.


What types of Tetracycline are available?

Tetracycline is commonly sold as film-coated tablets, red, round, and biconvex. On the transverse section, two layers are visible – outer-red and inner-yellow. One can also find an external ointment and ointment for the eyes. The most common dosage are 250mg and 500mg tablets.

What happens in case of an overdose?

With an overdose of the drug, the above side effects may increase in their appearance and strength. The treatment is purely symptomatic.

How fast does Tetracycline act?

After oral administration, 60-80% of the dose is absorbed. It is rapidly distributed in most tissues and body fluids. The absorption rate is 75-77%. However, when taking it with food, the absorption decreases. In just 2 to 3 hours, the substance will reach its highest concentration (it may take 2-3 days to achieve therapeutic concentration).