Tetracycline (released to market as regular Tetracycline pills or capsules, also differently branded as Sumycin, Wesmycin, and Achromycin) is a special antibiotic that fights against acne, Helicobacter pylori, and bacterial infections. It is sold under prescription. This medication achieves its effect by means of suppressing bacteria's function of protein production, thus preventing bacteria from reproduction and durable existence. Among tetracycline's possible side are tiredness, nausea, and vomiting.

The medicine is approved for ages 8 and above. When treating 7 year old or younger children with tetracycline, an everlasting staining of grayish-brown color can be caused to teeth.

A few companies are vendors of tetracycline. Among these are: Par Pharmaceuticals, Bristol-Myers Squibb, Mylan Pharmaceuticals, Teva Pharmaceuticals.

Treated people must be instructed that antibacterial medications such as Sumycin '250' and Sumycin '500' pills (Tablets of Tetracycline Hydrochloride) are intended exclusively for treatment of bacterial contagions. They are totally inappropriate for viral diseases (for instance, usual cold). Also, regardless of the fact that patients usually start feeling better at the very beginning of therapy, it should be accentuated that Sumycin '250' and Sumycin '500' pills (Tablets of Tetracycline Hydrochloride) are to be taken in exact accordance to prescription. Leaving the treatment course uncompleted or skipping doses may lead to (1) decrease of immediate treatment success probability (2) increase of probability that bacteria will become resistant to Sumycin '250' and Sumycin '500' pills (Tablets of Tetracycline Hydrochloride) and thus will no longer be treatable by this medication or other antibacterial medicines afterwards.


Various infections can be treated by Tetracycline under prescription. Among possible usages of the medicine are:

Infections of bacterial origin

Lyme disease
Lyme disease
The most common prescription of tetracycline is given to patients with bacterial infections. Among these infections are:
For individuals having an allergy to penicillin, tetracycline can serve well as a substitute for penicillin for treatment of such infections as:
Uncommon infections of bacterial origin can also be treated by tetracycline in many cases. Infections of virus origin, for example, common cold, influenza, stomach flu cannot be treated by tetracycline, since the medicine is not effective against those.


Acne of moderate to severe types can be treated with tetracycline under prescription. The medicine is in the group of tetracyclines along with doxycycline and minocycline antibiotics. It is not advised to treat other types of acne with tetracycline.

Tetracycline effect on acne explained
Acne is an infection of oil glands on the skin. It starts when a gland's follicle gets blocked with excess oil, dead cells of skin, and bacteria. As a result a pimple appears on the skin surface. Acne disease is described as continuous occurrence of several pimples in the same zone. Delaying of acne treatment may lead to problematic consequences such as further infections, skin pain, and scarring. Using tetracycline helps to control acne by means of suspending bacteria growth thus reducing swelling and pimples number.

Comparison of Tetracycline versus other anti-acne antibiotics
Considering the seriousness of condition, various medicines can be prescribed for treating acne. In cases of moderate-to-severe extent of disease, oral antibiotics are used. Among other antibiotics widely used in acne treatment are:
Acne drugs
Acne drugs
  • Erythromycin
  • Clindamycin
  • Minocycline
  • Doxycycline

Tetracycline is often prescribed as the first attempt of acne treatment owing to its high effectiveness and lower cost compared to similar medicines.

Suggested tetracycline dose in case of moderate to severe condition is 125 mg to 500 mg, and such dose should be taken two times a day. It is advised that the treatment lasts not shorter than 3 months to achieve maximum effect, and the course may be prolonged if needed. As soon as the condition changes for the better, doctors usually reduce the rate of taking the medicine to one time per day.

Helicobacter Pylori Infections

This kind of bacteria causes tissue disease expressed in a form of peptic ulcers which can occur in the foremost portion of the intestines (known as duodenum) or in the stomach. Going through a composite treatment course of tetracycline, metronidazole, bismuth subsalicylate (Pepto Bismol), and a proton pump inhibitor or H2-blocker usually kills Helicobacter Pylori (H. Pylori). For this reason, your doctor is likely to prescribe tetracycline as one of treating components against H. Pylori in case you are currently diagnosed with peptic ulcer disease or if you have had this disease 5 or less years ago. Regardless of severity of H. Pylori infection, it is advised to begin treatment as soon as possible to minimize risk of peptic ulcers formation.


Tetracycline dosages
Tetracycline dosages
Individual dosage for treatment with Tetracycline should be decided by a doctor. The following factors are considered when choosing the dose:
  • Patient's age
  • Patient's condition
  • Reliability of kidney function
  • Possible interference with other medications

Following the doctor's prescription is important, and you should not increase or decrease the dose by yourself.

Patients are advised to stick to a constant schedule of taking this medicine so the level of the antibiotic maintained in your organism is even throughout a day. It is generally preferred to take it without food: one hour ahead of a meal or two hours later. In case of stomach discomfort, it is acceptable to take this drug with food. Either way, remember to drink a cup of fresh water along with a dose.

Tetracycline will fail achieving its effect if you stop taking it before entire prescription is complete. In particular, do not take "I'm feeling better" as a sign to halt medication. If you don't finish your prescription, the infection won't be fully treated.

Always check the expiration date of the medicine prior to taking it, otherwise expired Tetracycline can intoxicate kidneys. Should you encounter any uncertainty in the course of treatment with this medicine, consult your pharmacist, doctor or nurse.

Tetracycline antibiotic

Choosing the dose for treating infections of H. Pylori

Tetracycline is effective at disposing of Helicobacter pylori only in conjunction with two other medicines, namely proton pump inhibitor and H2-blocker for neutralizing acid. In such treatment plan, normally Tetracycline should be taken in doses of 500 mg twice a day (maximum is 4 times) during 10 to 14 days.

Choosing the dose for fighting acne

The advised dose of this drug, when it is used to treat acne of moderate to severe degree, comprises between 125 mg and 500 mg taken two times a day. Anti-acne treatment course duration should not be less than 12 weeks to achieve best results. If acne responds to the treatment, your doctor is likely to drop your dosage to values around 125 mg.

Choosing the dosage in case of bacterial infections

The advised dose of the medicine for patients diagnosed with common types of bacterial infections comprises 250 to 500 mg, taken 4 times per day during 1 to 2 weeks. An extended treatment course may be suggested by your doctor if your condition is getting worse or has a chronic nature.

For kids aged 8 and up dose choice ranges between 25 and 50 mg per each kilogram of child weight. The dose is distributed in 4 takings a day. The treatment course for children normally isn't longer than 2 weeks.

Warnings and Precautions

Tetracycline may possibly interfere with effects of other medications. In particular, oral contraception pills effectiveness may be reduced when taken in combination with this medicine.

Note that this drug falls under D category in relation to pregnancy. D category medications are characterized by a considerable danger posed on a fetus if taken at the period of pregnancy. Nevertheless, the risk may be justified if mother suffers from a life-threatening condition that needs treatment with this medicine. Consulting with your doctor is obligatory if there is a chance that you may be pregnant before taking any dose of this medicine.

In circumstances such as dysfunctional liver or other health complications, the doctor can decide to avoid prescribing this drug or at least lowering its dose to minimum. It is known that Tetracycline is transferred via breast milk. Breastfeeding should be stopped if you are going through treatment with the medicine.

Among dangers that are posed to unborn children or children aged under 8 that take this medication is teeth color alteration, which is likely to stay permanent. This medicine can potentially provoke sudden diarrhea. Your doctor should be informed about the least sign of such symptom.

Pseudotumor cerebri (excessive brain pressure) is another condition that can be possibly caused by Tetracycline. It can be revealed with milky vision, nausea, migraine, and dizziness. Although stopping the drug usually cancels these symptoms, this should be done only under doctor's supervision.

While being on a treatment course with this medication, the risk of provoking other infections (e. g. vaginal yeast) sometimes arises. For this reason any deviations from your starting condition should be reported to doctor without delay. Inner skull pressure is known to increase under antibiotics medication such as Tetracycline. This unintended effect should not be ignored in any case. Your doctor should decide how to cope with this symptom.

Sporadic esophagus pain and ulcers can be provoked by this medication. But you can increase your resistance against these unwanted effects if you drink sufficient amount of liquid. Besides, keep yourself from taking the drug around the time you go to bed.

Unintended reactions on skin can occur while being on this medication and exposed to direct sunlight. Patients taking the drug are not advised to allow durable exposure of their skin to the sun. It is advised to wear clothes with long sleeves, hats, and sunglasses. Sunscreen with protection factor over 45 is suitable for protecting your weakened skin.

If you feel dizziness, vertigo or lightheadedness while going through the treatment course, keep yourself from driving and operating critical equipment for safety reasons.

Tetracycline precautions
Tetracycline precautions
After expiration date, this medicine is likely to become toxic, and taking it after that date will potentially do harm to your kidneys. You are strongly advised against taking Tetracycline if one or more of the following statements apply to you:
  • Your body displays an allergic reaction to tetracycline, or have records of allergies to similar drugs (including minocycline or doxycycline), and auxiliary ingredients in the medicine composition. Consult with your pharmacist or your doctor to obtain further information on content of auxiliary ingredients.
  • You are a child aged 8 and younger (unless an extreme cause requires use of it)
  • You are breastfeeding or going through pregnancy
  • Kidney dysfunction takes place
  • Liver dysfunction takes place

Consult your doctor before starting the treatment course in case you:
  • Have diseases of liver
  • Have diseases of kidneys
  • Are breastfeeding
  • Experienced allergic reaction to treatment before
  • Are potentially or sure to be pregnant
  • Have a surgery scheduled soon

Your doctor should be given comprehensive information regarding other drugs that you have prescriptions for, medications you take without prescriptions, oral contraception pills, vitamins, herbal add-ons, and blood-thinners.

Side Effects

Tetracycline side effects
Tetracycline side effects
Gastrointestinal: immense loose stools, diarrhea, anorexia, epigastric pain, nausea, vomiting, stomatitis, black hairy tongue, sore throat, enterocolitis, glossitis, hoarseness, dysphagia, and inflammatory scratches around anogenital area, such as pruritus ani and proctitis. Patients getting predominantly the tablet and capsule forms of the medicine had occurrences of esophageal ulceration and esophagitis. Majority of such patients reported to take the drug around the time they were going to bed. These reactions are not revealed so often after parenteral use though.

Renal toxicity: upsurges in BUN are known to happen and are considered dose-related.

Skin condition: rashes of erythematous and maculopapular kinds can be potentially provoked. Photosensitivity proved to increase for most patients. Extremely rare conditions to occur are: exfoliative dermatitis, discoloration of the nails and onycholysis.

Hepatic cholestasis: occurred only in a minor fraction of cases, tends to be associated with overly dosed medication.

Hematological (related to blood): there are records stating thrombocytopenia anemia, hemolytic anemia, thrombocytopenic purpura, eosinophilia and neutropenia being provoked while taking the drug.

Hypersensitivity to certain substances: reactions similar to serum sickness, anaphylaxis; rash, fever, as well as arthralgia; anaphylactoid purpura, urticaria, angioneurotic edema, systemic lupus erythematosus, pericarditis.

Other side effects: headache, weakness and dizziness.

When treatment course is extended, the medicine can potentially cause tiny brown-black staining of thyroid glands. Such discoloration is not accompanied with any abnormalities in thyroid function though. There were also records of intracranial hypertension in grown-ups and protruding fontanels in children.

Mechanism of action

Tetracycline formula
Tetracycline formula
Tetracyclines constrain protein production by hindering the interaction between charged aminoacyl-tRNA and the ribosome's A site. These drugs are predicament to the 30S subunit of microscopic ribosomes. Basically, they keep produced amino acids from being introduced into the emerging peptide chain. After stopping the medicine, its effect is reversible. Resistance towards tetracyclines is the result of alterations in permeability of the bacteriological cell wrapping. When it affects vulnerable cells, the medicine is absorbed from the surrounding plasma and is not easily expelled back from the cells. On contrary, cells that developed resistance, repel the medicine's transportation inside them and make it leave rapidly, thus preventing it from reaching concentrations sufficient for inhibition. Plasmids commonly display such behavior. In particular, mammalian cells show invincibility to the action of tetracyclines, since these have no 30S ribosomal subunits in their composition and as such do not allow the medicine to pile up in effective concentration.


Benjamin Minge Duggar
Benjamin Minge Duggar
The tetracyclines comprise a large class of antibiotics first discovered by Benjamin Minge Duggar as natural substances in 1945. It was then when first tetracycline antibiotic, chlortetracycline, was synthesized and studied in Lederle Laboratories. The first scientific description of the discovery was released to public in 1948.

Robert Woodward, a Professor from Harvard, had thoroughly examined the chemical composition of the similar chemical, oxytetracycline (Terramycin) in 1950. The scientist had a patent for its production, too. This discovery was made possible by a group of allied researchers (K.J. Brunings, C.R. Stephens, Francis A. Hochstein, Abraham Bavley, L.H. Conover, Peter P. Regna Richard, and Pasternack) who had been working for two years in the laboratory.

Pfizer concluded that it earned the right to hold a patent on tetracycline and documented its Conover claim in 1952. In 1953 Cyanamid documented its Boothe Morton claim for the same rights, and Heyden Chemicals later applied with its Minieri (in honor of the scientist P. Paul Minieri) in 1953. The latter case was tough for applicant, as the one to win the case would have to provide proofs beyond reasonable doubt in regard to timeline of inventions.

Drug Interactions

Tetracycline interactions
Tetracycline interactions
A list of medicines that can possibly interact with tetracycline is given below. Note that these are only the most common cases; your individual case may be different:
  • Penicillin
  • Aluminum/magnesium/calcium/iron products (such as iron supplements, antacids, laxatives, calcium supplements, or multivitamins)
  • Digoxin (Lanoxicaps, Digitek, Lanoxin)
  • Warfarin (Jantoven, Coumadin)
  • Methoxyflurane (Penthrane)
  • Triazolam (Halcion)
  • Cisapride (Propulsid)
  • Cyclosporine (Neoral, Sandimmune, Restasis, Gengraf)
  • Midazolam
  • Mirtazapine (Remeron SolTab, Remeron)
  • Nefazodone
  • Lovastatin (Mevacor, Altoprev)
  • Quinidine
  • Tacrolimus (Protopic, Prograf)
  • Venlafaxine (Effexor, Effexor XR)
  • Sildenafil (Revatio, Viagra)
  • Nateglinide (Starlix)
  • Simvastatin (Zocor)
  • Thioridazine
  • Mesoridazine (Serentil)
  • Pimozide (Orap)
  • Calcium channel blockers
  • Bismuth subsalicylate (Pepto Bismol)
  • Barbiturates
  • Phenytoin (Phenytek, Dilantin)
  • Nevirapine (Viramune)
  • Didanosine (Videx EC, Videx)
  • Quinapril (Accupril)
  • Aminoglutethimide (Cytadren)
  • Sucralfate (Carafate)
  • Carbamazepine (Epitol, Equetro, Tegretol, Carbatrol, Tegretol-XR)
  • Oral contraceptives

More details

Being an antibiotic itself, it is not advised to combine taking of Penicillin with Tetracycline. The main reason behind it is that penicillin will be weaker and therefore worse at fighting infection. Your doctor can always suggest alternative medication on request.

Magnesium/Iron/Aluminum/Calcium -containing products
The listed elements found in meals or food are proven to worsen the effectiveness of Tetracycline. Therefore, products containing these elements have some negative features if taken with the drug It would be vise to keep yourself from having a meal containing an element from the list at least 2 hours ahead of the meal. Examples of substances containing these elements are: antacids, multivitamins, iron or calcium supplements, and laxatives.

When you take tetracycline in combination with digoxin, your organism can potentially metabolize the two drugs in a considerable deviation from intended course of things. A consultation with your doctor about this matter is suggested.

Should you take warfarin and tetracycline in combination, your organism potentially metabolizes the drugs in contrary to indented way. Your doctor is likely to set monitoring over your prothrombin time and INR (telling how well your organism is clotting) to adjust treatment plan if necessary.

This anesthetic is used for surgeries. The bad thing is that when Methoxyflurane and tetracycline combine, they form a compound that can endanger the normal functioning of kidneys.

Triazolam, Tacrolimus, Sildenafil, Cyclosporine, Midazolam, Cisapride, Mirtazapine, Quinidine, Calcium Channel Blockers, Nefazodone, Nateglinide, Venlafaxine, Thioridazine, Simvastatin, Pimozide, Lovastatin, Mesoridazine.
In case you are prescribed to take both tetracycline and one or more of the drugs in the list above, your organism can potentially metabolize them in an unintended way, resulting in considerably increased content of these drugs in your body. Your doctor can insist on constant supervision of your condition changes in order to adapt treatment correspondingly.

Barbiturates, Nevirapine, Sucralfate, Bismuth Subsalicylate, Quinapril, Didanosine, Carbamazepine, Phenytoin, Nafcillin, Aminoglutethimide
In case you are prescribed to take both tetracycline and one or more of the drugs in the list above, your organism can potentially metabolize them in an unintended way, resulting in considerably decreased content of tetracycline in your body. Your doctor can insist on constant supervision of your condition changes in order to adapt treatment correspondingly.

Oral contraception pills
In a case you are on tetracycline medication while also sticking to oral contraception drugs, tetracycline is likely to reduce the contraceptive effectiveness. Do not ignore an option to discuss it with your doctor to find a way around this problem.


All possible drug interactions with tetracycline are not limited to medicines listed above. Each case is individual and should be discussed with your pharmacist or doctor.
Madnix . Wildsultan

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User discussion about Tetracycline

12 April 2012
I have problems with the skin. The doctor prescribed me tetracycline or erythromycin. In pharmacies, the difference in price is by half. If both are good, why should we pay more?
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22 April 2012
My baby is 2 months old.On the 8th day after birth, I noticed that her eye was watery. On the 2nd week the doctor prescribed Tetracycline. We applied it for two weeks but there was no result. I read that kids can recover by themselves. Is that right? Or shall we take another medicine?
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13 August 2012
One year I was using this drug (500 mg) two times a day. To my regret I was forced to stop usage of it and to find alternate drug (Biaxin). But after some time my organism developed a resistant to Biaxin and I changed it.
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18 September 2012
This drug is amazing especially for adult acne. Now I have no physical defects and I am happy. And, I did not find any side effects (according to the list).
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