Tetracycline include -Tetracycline, Democlocycline, Doxycycline, Methacycline, Minocycline, Oxytetracycline
Interacting drugs - summary
Aluminium salts/ Calcium salts / Magnesium salts
impair absorption of tetracyclines due to formation of poorly soluble
chelate possibly decreasing the antimicrobial efficay
serum levels of tetracyclines decreased , possibly resulting
in a decreased anti-infective response. Doxycycline not affected
increase the hypoprothrombinenic effect of concurrent anticoagulants
Monitor prothrombin activity
Barbiturates / Carbamzepine / Hydantoins
increase the rate of metabolism and therefore decrease the
half-life and serum levels of doxycycline. Antimictobial efectiveness
pharmacologic effects of these agents decreased by cimetidine
due to decreased absorption. Antimicrobial effectiveness decreased
tetracyclines increase the serum levels of digoxin in a small portion
(<10% of patients this could lead to digoxin toxicity. These effects
last for few months after tetracycline is discontinued
tetracycline educe insulin requirements. Monitor blood glucose
Iron salts + Tetracycline or Tetracycline + Iron salts
coadmin decrease absorption and serum levels
levels of trtracyclines. Absorption of iron salts decreased
tetracycline increase or decrease lithium levels. Monitor serum
and tetracycline coadministration increase the nephrotoxic effects
of both drugs. Avoid this combination
Coadministration of tetracycline with OCs decrease the
pharmacologic effects of the OCs. Menstrual irregularities
(spotting, breakthrough bleeding), may occur. An alternate
or additional form of birth control advisable
Tetracycline derivatives impair bactercidal effect of Penicillins
Avoid concurrent administration
renal clearance increased due to alkalinazation of urine
resulting in increased pharmacologic effect
Bile salts seques
serum levels of tetracycline decreased by colestipol
Quinalapril + Tetracycline
tetracycline absorption reduced 28% to 37% possibly due to high
magnesium content of Quinalapril tablets
Bismuth sub salicylate
Bismuth may decrease GI absorption and bioavailability of
tetracyclines, reducing their efficacy.
Tetracycline + Pancuronium
Parentral/intraperitoneal administration of high doses of certain
antibiotics may produce neuromuscular block onnits own. If these
agents are used preoperatively or in conjunction with pancuronium
during surgery, unexpected prolongation of neuromuscular block is
parentral/intraperitoneal admininistration of of high doses of certain
antibiotics may intensify or produce neuromuscular blockade on their
own. If these or newly introduced are used with vercuronium during
surgery, consider the possibility of unexpected prolongation of
Tetracycline + Pipecuronium
Parentral/Peritoneal administration of high doses of cetain antibitotics
intensify or produce neuromuscular blockade on their own.
If these or other newly introduced antibiotics are used with
pipercuronium during surgery, consider prolongation of
neuromuscular block, a possiblity.
charcoal can reduce the absorption of the sulfonylureas depending
on the clinical situation, this will reduce their efficacy or toxicity.
do not simultaneously administer didanosine tablets or pediatric
powder for oral solution of tetracycline
FIXED DOSE COMBINATIONS APPROVED BY DCG(I)
FROM JANUARY 1961 TILL NOVEMBER 2014
Name of Drug Indication Date of Approval
Tetracycline HCL 250mg + Jan 1969
Boxyquinoline 200mg +
Infections caused by rickettsiae(Typhus fever and typhus group),infections caused by gram negative micro-organisms- E.coli, gram positive micro-organisms. skin and soft tissue infections.
Tetracycline include -Tetracycline, Democlocycline, Doxycycline, Methacycline, Minocycline, Oxytetracycline
GI- Oral and parentral- anorexia, nausea, vomiting, diarrhea, epigastric dustress, bulky loose stools,stomatisis, sore throat, glossitis, hoarsenmess, black hairy tingue, dyspepsia, enterocolitis, infalmmatory lesions (with monilial overgrowth) in the anogenial region, including proctitis, and pruritis
Oral- Esophageal ulcers, most commonly in patients with an esophageal obstructive element or hiatial hernia. Having the patient remain standing for at least 90 seconds after medication ingestin and taking the medication with a full glass of water at least 1 hour before going to bed may minimize this problem.
Dermatologic- Maculopapular and erytthematous rashes, exfoliative dermatitis (uncommon).
Photosensitivity Onycholysis and discoloration of the nails (rare) Blue grey pigmentation of the skin and mucous membranes has been reported primarily with minocycline
Stevens Johnson syndrome has occured with minocycline
Renal- Dose related Rise in BUN, acute renal failure, interstitial nephritis, diabetic insipidus
Hepatic- fatty liver, hepatotoxicity, hepatitis(rare), increases in liver enzymes. Hepatic cholestatis(rare) is usually
associated with high dosage levels.
CNS- bulging fontaneal, convulsions, dizziness, headache, paresthesia, pseudomotor cerebri,
sedation, vertigo, myasthenia syndrome ,
Hypersensitivity- urticaria, angioneurotic edema, anaphylaxis, anaphylactoid purpura, pericarditis,
excacerbated sytemic lupus erythmatosus, polyarthalgia, serum sickness like reactions eg fever,
arthralgia, pulmonary esosinophilia.
Hematologic- hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, neutropenia,
Miscellaneous- pseudotumor cerebri(adults), bulging fontaneal (infants) Nephrogenic diabetes
insipidus has been reported with democycline. When given over protracted periods, tetracycline
reportedly produce brown-black microscopic discoloration of thyroid glands.
No abnormal tyroid function studies are known to occur.
Local- irritation may occur with IM administration.
Hypersens, SLE, pregnancy, neonates.
Pseudotumor cerebri- (benign intracranial hypertension) in adults has been associated with tetracycline use.Usual clinical manifestations are headache and blurred vision. Bulging fontanels have been associated with teracycline use in
Outdated products- under no circumstances should outdated tetracycline be administred , the degradation products of tetracycline are highly nephrotoxic and have on occassion produced a Faconi-like syndrome.
Laboratory tests- in sexually transmitted diseases when coexistent syphilis is suspected, peform darkfield examination befoire tretment is started and repeat blood serolgy monthly for at least 4 months.
Superinfection- Use of antibiotics (especially prolonged or repeated therapy) may result in bacterial or fungal overgrowth. of nonsuseptible organisms. Such overgrowth may result in secondary infection.
Photosensitivity- Photosensitivity manifested by an exaggerated sunburn reaction has been observed in some individuals taking tetracyclines. Advise patients who are apt to be exposed to direct sunlight or ultraviolet light, that this reaction can occur. Discontune treatment at the first evidence of skin eryrthema.
Parentral therapy- reserve for situations in which oral therapy is not indicated
Nephrogenic diabetes insipidus- adminstration of democlocycline has resulted in appearance of diabetes insipidus syndrome.The sydrome is dose dependent and reversible on discontinuation of therapy
Hazardous tasks- lightheadedness, dizziness, or vertogo may occur with minocycline. Patients should observe caution while driving or performing tasks which are hazardous.
Renal function impairment- if renal impairment exists, even usual doses may lead to excessive systemic accumulation of the tetracyclines.(with exception of doxycycline and minocycline). Use lower than usual doses if therapy is prolonged, drug serum levels may be advisable.
Hepatic function impairment- 2g/day IV can be extremely dangerous. In the presence of renal dysfunction and particularly in pregnancy IV tetracycline > 2g/day has been asociated with death secondary to liver failure. Do not prescrbe other potentially hepatotoxic drugs concomittantly.
Pregnancy- Tetracyclines should not be used during pregnancy.
Lactation- Because of potential for serious adverse reactions decide whether to discontune nursing or discontinue the drug
Children- tetracyclines should not generally be used in children under 6 years ofage, inless other drugs are not likely to be effective or are contraindicated.
Dosages/ Overdosage Etc:
Infections caused by rickettsiae(Typhus fever and typhus group),infections caused by
gram negative micro-organisms- E.coli, gram positive micro-organisms. skin and soft tissue infections.
Usual oral adult maintenance dose- 250mg 6 hourly or 500mg 6 to 12hourly. For severe
infections- 500mg 4 times a day.
Children over 8 years of age- Daily dose is 10 to 20mg/lb(25 to 50mg/kg) in 4equal doses.
Parentral- IM inject deeply into a large muscle mass as the gluteal region as inadvertant injection into subcutaneous or fat layer may cause pain. Usual daily dosage - 250mg once every 24 hours, or 300mg in divided doses at 8 to 12 hourly intervals.
The initial reconstituted solutions are stable at Room temp. for 12 hours, without
significant loss of potency. Administer the final dilution immediately.
1. If you miss a dose of this medicine, take it as soon as possible.
2. However, if it is almost time for next dose, skip the missed dose and go back to your regular dosing schedule.
3. Do not double doses.
1.Indian Drug Manufacturers Association (IDMA)
Phone- 022- 24944624/ 24974308
Fax- 022- 24950723
2.Bulk Drug Manufacturers Association (India)(BDMA)
Phone - 040-23703910/ 23706718
Photodermatitis ( 260 )
Photodermatitis can develop as the result of contact with many plants ( belonging prinipally to the families Rutaceae and Umbelliferae eg. certain times ,parsely, celery, bishops weed, figs ) ans subsequent exposure of the skin to sunlight. The photodermatitis involves a mild -to -sever erythematous reaction with otr without vesicles or bullae.
Drugs causing adverse reactions- ( 385 )
1. Tetracyclines, particularly democycline
8. Nalidixic acid
9. Oral contraceptives
Drugs causing dental discolouration- ( 385 )
1. Take on empty stomach, at least 1 hour before or 2 hours after a meas(doxycycline and
minicycline may be taken with food or milk.. Take with a full glass of water(240ml).
2. Avoid simultaneous dairy products(milk.cheese) antacids, laxatives, or iron-containing
products. If an antacid must be taken, take at least 2 hours before or after tetracycline.
3. Avoid prolonged exposure to sunlight or sunlamps; may cause photosensitivity(especially
5. Allergies- tell your doctor if you have ever had any unusual or allergic reaction to tetracycline. Also tell your doctor if you are allergic to any other substances, such as foods, presevatives or dyes.
6.Pregnancy- use not recommended during the last half of pregnancy
7.Breast feeding- use not recommended since tretacycline pass into the breast milk.
8.Children- should not be given to children upto 8 years of age unless directed by the childs doctor.
9. Elderly- no specific information comparing use of tetracycline in the elderly with use in younger groups.
10. Other medicines -
Tell your doctor if you taking
Calcium supplements or
Choline and magnesium salicylates
Iron containing medicine or
Magnesium salicylates - use of these medicines with tetracycline may increase the effect of tetracycline
Oral contraceptives- use of contraceptives with tetracycline mauy decrease the effect and increase the chance of unwanted pregnancy.
11. Other medical problems -
Diabetes insipidus - democycline may make the condition worse
Kidney disease - patients with kidney disease may have an increased chance of side effects
Liver disease - patients with liver disease may have an increased chance of side effects if they use doxycycline or minocycline
12. Missed dose -
If you miss a dose of this medicine, take it as soon as possible. however, if it is almost time for the next dose, skip the missed dose. Do not double doses.
13. Storage -
Keep out of reach of children. Store away from heat or direct sunlight. Do not store
the capsule in bathroom, near the kitchen sink, or in other damp places.
14. Outdated medicines -
Do not keep outdated medicine or medicine no longer needed. Be sure that any
discarded medicine is out of reach of children.
Drug Facts And Comparisons(2010)
The tetracyclines are bacteriostatic. They exert their antimicrobial effect by inhibition of protein synthesis. Tetracyclines are effective against a wide range of gram-negative and gram-positive organisms.
Tetracyclines are adequately but incompletely absorbed in children and adults in the
fasting state. Percentage of oral dose absobed is highest for doxycycline and minocycline and intermediate for oxytetracycline. Tetrcyclines are concentrated by the liver inthe bile and excreted in the urine and feces, as largely unchanged.
Absorption Cmax Tmax Protein Serum Excreted
% (mcg/mL) (h) binding half-life in urine
(%) (h) (%)
60-80% 1.5 to1.7 3 to4 35 to90 16 nd
90-100 2.6(hyclate) 2(hyclate) 80 to90 18 to22 40
90-100 2.1to 5.1 1to 4 75 11to 22 5 to 10
60-80 nd 2 to4 20 to65 6to 12 20 to 55
Interaction with Food:
Food and some dairy products interfere with the absorption of tetracyclines. Administer oral tetracycline 1 hour before or 2 hours after meals.
Doxycycline has low affinity for calcium binding. Gastrointestinal absorption of minocycline and doxycycline is not significantly affected by food or dairy products.
Pregnancy and lactation:
Tetracyclines should not be used during pregnancy. They readily cross the placenta. Tetracyclines are found in fetal tissues and can have toxic effects on the developing fetus.
Tetracyclines are excreted in breast milk. Because of the potential for serious adverse effects decide whether to discontinue nursing or discontinue the drug.
Tetracyclines should not generally be used in children under 8years of age, unless other drugs are not likely to be effective, or are contraindicated.