Tetracycline

 Risk Factor: D
 Class: ANTI-INFECTIVES / Tetracyclines

Contents of this page:

Fetal Risk Summary
Breast Feeding Summary
References
Questions and Answers

Fetal Risk Summary

Tetracyclines are a class of antibiotics that should be used with extreme caution, if at all, in pregnancy. The following discussion, unless otherwise noted, applies to all members of this class. Problems attributable to the use of the tetracyclines during or around the gestational period can be classified into four areas:

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• Adverse effects on fetal teeth and bones
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• Maternal liver toxicity
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• Congenital defects
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• Miscellaneous effects\t

Placental transfer of a tetracycline was first demonstrated in 1950 (1). The tetracyclines were considered safe for the mother and fetus and were routinely used for maternal infections during the following decade (2,3,4 and 5). It was not until 1961 that an intense yellow-gold fluorescence was observed in the mineralized structures of a fetal skeleton whose mother had taken tetracycline just before delivery (6). Following this report, a 2-year-old child was described whose erupted deciduous teeth formed normally but were stained a bright yellow because of tetracycline exposure in utero (7). Fluorescence under ultraviolet light and yellow-colored deciduous teeth that eventually changed to yellow-brown were associated with maternal tetracycline ingestion during pregnancy by several other investigators (8,9,10,11,12,13,14,15,16,17,18,19,20,21 and 22). An increase in enamel hypoplasia and caries was initially suspected but later shown not to be related to in utero tetracycline exposure (14,15,22). Newborn growth and development were normal in all of these reports, although tetracycline has been shown to cause inhibition of fibula growth in premature infants (6). The mechanism for the characteristic dental defect produced by tetracycline is related to the potent chelating ability of the drug (13). Tetracycline forms a complex with calcium orthophosphate and becomes incorporated into bones and teeth undergoing calcification. In the latter structure, this complex causes a permanent discoloration, as remodeling and calcium exchange do not occur after calcification is completed. Because the deciduous teeth begin to calcify at around 5 or 6 months in utero, use of tetracycline after this time will result in staining.

The first case linking tetracycline with acute fatty metamorphosis of the liver in a pregnant woman was described in 1963 (23), although two earlier papers reported the disease without associating it with the drug (24,25). This rare but often fatal syndrome usually follows IV dosing of more than 2 g/day. Many of the pregnant patients were being treated for pyelonephritis (24,25,26,27,28,29,30,31,32,33,34,35,36 and 37). Tetracycline-induced hepatotoxicity differs from acute fatty liver of pregnancy in that it is not unique to pregnant women and reversal of the disease does not occur with pregnancy termination (38). The symptoms include jaundice, azotemia, acidosis, and terminal irreversible shock. Pancreatitis and nonoliguric renal failure are often related findings. The fetus may not be affected directly, but as a result of the maternal pathology, stillborns and premature births are common. In an experimental study, increasing doses of tetracycline caused increasing fatty metamorphosis of the liver (39). The possibility that chronic maternal use of tetracycline before conception could result in fatal hepatotoxicity of pregnancy has been raised (36). The authors speculated that tetracycline deposited in the bone of a 21-year-old patient was released during pregnancy, resulting in liver damage.

In a surveillance study of Michigan Medicaid recipients involving 229,101 completed pregnancies conducted between 1985 and 1992, a large number of newborns had been exposed to the tetracycline group of antibiotics during the 1st trimester (F. Rosa, personal communication, FDA, 1993). For four tetracyclines (T=tetracycline; D=doxycycline; O=oxytetracycline; M=minocycline), specific data were available for six defect categories, including (observed/expected):

	T	D	O	M
Number of exposures	1004	1795	26	181
Number of major defects	47	78	1	8
Percent	4.7%	4.3%	3.8%	4.4%
Number of major defects expected	43	76	1	7
Cardiovascular defects	12/10	20/18	0/0.3	2/2
Oral clefts	1/2	0/3	0/0	1/0.5
Spina bifida	0/0.5	2/1	0/0	0/0
Polydactyly	5/3	7/5	0/0	0/0.5
Limb reduction defects	1/2	0/3	0/0	0/0.5
Hypospadias	1/2	4/4	0/0	0/0.5

These data do not support an association between the drugs and the specific malformations evaluated.

The Collaborative Perinatal Project monitored 50,282 mother-child pairs, 341 of whom had 1st-trimester exposure to tetracycline, 14 to chlortetracycline, 90 to demeclocycline, and 119 to oxytetracycline (40, pp. 297313). For use anytime in pregnancy, 1,336 exposures were recorded for tetracycline, 0 for chlortetracycline, 280 for demeclocycline, and 328 for oxytetracycline (40, p. 435). The findings of this study were as follows:

Tetracycline: Evidence was found to suggest a relationship to minor, but not major, malformations. Three possible associations were found with individual defects, but the statistical significance of these is unknown (40, pp. 472, 485). Independent confirmation is required to determine the actual risk.

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• Hypospadias (1st trimester only) (5 cases) \t
• Inguinal hernia (25 cases) \t
• Hypoplasia of limb or part thereof (6 cases)

Chlortetracycline: No evidence was found to suggest a relationship to large categories of major or minor malformations or to individual defects. However, the sample size is extremely small, and safety should not be inferred from these negative results.

Demeclocycline: No evidence was found to suggest a relationship to large categories of major or minor malformations, but the sample size is small (40, pp. 297313). Two possible associations were found with individual defects, but the statistical significance of these is unknown (40, pp. 472, 485). Independent confirmation is required to determine the actual risk.

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• Club foot (1st trimester only) (3 cases) \t
• Inguinal hernia (8 cases)

Oxytetracycline: Evidence was found to suggest a relationship to large categories of major and minor malformations (40, pp. 297313). One possible association was found with individual defects, but the statistical significance of this is unknown (40, pp. 472, 485). Independent confirmation is required to determine the actual risk.

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• Inguinal hernia (14 cases)

In 1962, a woman treated with tetracycline in the 1st trimester for acute bronchitis delivered an infant with congenital defects of both hands (41,42). The mother had a history of minor congenital defects on her side of the family and doubt was cast on the role of the drug in this anomaly (43). A possible association between the use of tetracyclines in pregnancy or during lactation and congenital cataracts has been reported in four patients (44). The effects of other drugs, including several antibiotics, and maternal infection could not be determined, and a causal relationship to the tetracyclines seems remote. An infant with multiple anomalies whose mother had been treated for acne with clomocycline daily during the first 8 weeks of pregnancy has been described (45). Some of the defects, particularly the incomplete fibrous ankylosis and bone changes, made the authors suspect this tetracycline as the likely cause.

Doxycycline has been used for 10 days very early in the 1st trimester for the treatment of Mycoplasma infection in a group of previously infertile women (46). Dosage was based on the patient's weight, varying from 100300 mg/day. All 43 of the exposed liveborns were normal at 1 year of age. Bubonic plague occurring in a woman at 22 weeks' gestation was successfully treated with tetracycline and streptomycin (47). Long-term evaluation of the infant was not reported.

A 1997 report examined the question of doxycycline-induced teratogenicity in the large population-based data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 19801992 (48). Some mild defects were excluded, including hemangiomas and minor malformations. Moreover, although an extensive retrospective assessment of drug use during pregnancy was performed, a history of tobacco and alcohol exposure was not obtained because the accuracy of these data were believed to have low validity (48). Among the 32,804 pregnant women who had normal infants (controls), 63 (0.19%) had taken doxycycline, whereas 56 (0.30%) of the 18,515 women who delivered infants with congenital anomalies had taken the antibiotic (p=0.01). A case-control pair analysis of exposures during the 2nd and 3rd months of gestation, however, did not show a significant difference among the groups in any of the malformation types.

Under miscellaneous effects, two reports have appeared that, although they do not directly relate to effects on the fetus, do directly affect pregnancy. In 1974, a researcher observed that a 1-week administration of 500 mg/day of chlortetracycline to male subjects was sufficient to produce semen levels of the drug averaging 4.5 g/mL (49). He theorized that tetracycline overdose could modify the fertilizing capacity of human sperm by inhibiting capacitation. Finally, a possible interaction between oral contraceptives and tetracycline resulting in pregnancy has been reported (50). The mechanism for this interaction may involve the interruption of enterohepatic circulation of contraceptive steroids by inhibiting gut bacterial hydrolysis of steroid conjugates, resulting in a lower concentration of circulating steroids.

Breast Feeding Summary

Tetracycline is excreted into breast milk in low concentrations. Milk:plasma ratios vary between 0.25 and 1.5 (4,51,52). Theoretically, dental staining and inhibition of bone growth could occur in breast-fed infants whose mothers were consuming tetracycline. However, this theoretical possibility seems remote, because tetracycline serum levels in infants exposed in such a manner were undetectable (<0.05 g/mL) (4). Three potential problems may exist for the nursing infant even though there are no reports in this regard: modification of bowel flora, direct effects on the infant, and interference with the interpretation of culture results if a fever workup is required. The American Academy of Pediatrics considers tetracycline to be compatible with breast feeding (53).

References

1. Guilbeau JA, Schoenbach EG, Schaub IG, Latham DV. Aureomycin in obstetrics: therapy and prophylaxis. JAMA 1950;143:5206.
2. Charles D. Placental transmission of antibiotics. J Obstet Gynaecol Br Emp 1954;61:7507.
3. Gibbons RJ, Reichelderfer TE. Transplacental transmission of demethylchlortetracycline and toxicity studies in premature and full term, newly born infants. Antibiot Med Clin Ther 1960;7:61822.
4. Posner AC, Prigot A, Konicoff NG. Further observations on the use of tetracycline hydrochloride in prophylaxis and treatment of obstetric infections. In Antibiotics Annual, 195455. New York, NY: Medical Encyclopedia, 1955:5948.
5. Posner AC, Konicoff NG, Prigot A. Tetracycline in obstetric infections. In Antibiotics Annual, 195556. New York, NY: Medical Encyclopedia, 1956:3458.
6. Cohlan SQ, Bevelander G, Bross S. Effect of tetracycline on bone growth in the premature infant. Antimicrob Agents Chemother 1961:3407.
7. Harcourt JK, Johnson NW, Storey E. In vivo incorporation of tetracycline in the teeth of man. Arch Oral Biol 1962;7:4317.
8. Rendle-Short TJ. Tetracycline in teeth and bone. Lancet 1962;1:1188.
9. Douglas AC. The deposition of tetracycline in human nails and teeth: a complication of long term treatment. Br J Dis Chest 1963;57:447.
10. Kutscher AH, Zegarelli EV, Tovell HM, Hochberg B. Discoloration of teeth induced by tetracycline. JAMA 1963;184:5867.
11. Kline AH, Blattner RJ, Lunin M. Transplacental effect of tetracyclines on teeth. JAMA 1964;188:17880.
12. Macaulay JC, Leistyna JA. Preliminary observations on the prenatal administration of demethylchlortetracycline HCl. Pediatrics 1964;34:4234.
13. Stewart DJ. The effects of tetracyclines upon the dentition. Br J Dermatol 1964;76:3748.
14. Swallow JN. Discoloration of primary dentition after maternal tetracycline ingestion in pregnancy. Lancet 1964;2:6112.
15. Porter PJ, Sweeney EA, Golan H, Kass EH. Controlled study of the effect of prenatal tetracycline on primary dentition. Antimicrob Agents Chemother 1965:66871.
16. Toaff R, Ravid R. Tetracyclines and the teeth. Lancet 1966;2:2812.
17. Kutscher AH, Zegarelli EV, Tovell HM, Hochberg B, Hauptman J. Discoloration of deciduous teeth induced by administrations of tetracycline antepartum. Am J Obstet Gynecol 1966;96:2912.
18. Brearley LJ, Stragis AA, Storey E. Tetracycline-induced tooth changes. Part 1. Prevalence in pre-school children. Med J Aust 1968;2:6538.
19. Brearley LJ, Storey E. Tetracycline-induced tooth changes. Part 2. Prevalence, localization and nature of staining in extracted deciduous teeth. Med J Aust 1968;2:7149.
20. Baker KL, Storey E. Tetracycline-induced tooth changes. Part 3. Incidence in extracted first permanent molar teeth. Med J Aust 1970;1:10913.
21. Anthony JR. Effect on deciduous and permanent teeth of tetracycline deposition in utero. Postgrad Med 1970;48:1658.
22. Genot MT, Golan HP, Porter PJ, Kass EH. Effect of administration of tetracycline in pregnancy on the primary dentition of the offspring. J Oral Med 1970;25:759.
23. Schultz JC, Adamson JS Jr, Workman WW, Normal TD. Fatal liver disease after intravenous administration of tetracycline in high dosage. N Engl J Med 1963;269:9991004.
24. Bruno M, Ober WB. Clinicopathologic conference: jaundice at the end of pregnancy. NY State J Med 1962;62:3792800.
25. Lewis PL, Takeda M, Warren MJ. Obstetric acute yellow atrophy. Report of a case. Obstet Gynecol 1963;22:1217.
26. Briggs RC. Tetracycline and liver disease. N Engl J Med 1963;269:1386.
27. Leonard GL. Tetracycline and liver disease. N Engl J Med 1963;269:1386.
28. Gough GS, Searcy RL. Additional case of fatal liver disease with tetracycline therapy. N Engl J Med 1964;270:1578.
29. Whalley PJ, Adams RH, Combes B. Tetracycline toxicity in pregnancy. JAMA 1964;189:35762.
30. Kunelis CT, Peters JL, Edmondson HA. Fatty liver of pregnancy and its relationship to tetracycline therapy. Am J Med 1965;38:35977.
31. Lew HT, French SW. Tetracycline nephrotoxicity and nonoliguric acute renal failure. Arch Intern Med 1966;118:1238.
32. Meihoff WE, Pasquale DN, Jacoby WJ Jr. Tetracycline-induced hepatic coma, with recovery. A report of a case. Obstet Gynecol 1967;29:2605.
33. Aach R, Kissane J. Clinicopathologic conference: a seventeen year old girl with fatty liver of pregnancy following tetracycline therapy. Am J Med 1967;43:27483.
34. Whalley PJ, Martin FG, Adams RH, Combes B. Disposition of tetracycline by pregnant women with acute pyelonephritis. Obstet Gynecol 1970;36:8216.
35. Pride GL, Cleary RE, Hamburger RJ. Disseminated intravascular coagulation associated with tetracycline-induced hepatorenal failure during pregnancy. Am J Obstet Gynecol 1973;115:5856.
36. Wenk RE, Gebhardt FC, Behagavan BS, Lustgarten JA, McCarthy EF. Tetracycline-associated fatty liver of pregnancy, including possible pregnancy risk after chronic dermatologic use of tetracycline. J Reprod Med 1981;26:13541.
37. King TM, Bowe ET, D'Esopo DA. Toxic effects of the tetracyclines. Bull Sloane Hosp Women 1964;10:3541.
38. Kaplan MM. Acute fatty liver of pregnancy. N Engl J Med 1985;313:36770.
39. Allen ES, Brown WE. Hepatic toxicity of tetracycline in pregnancy. Am J Obstet Gynecol 1966;95:128.
40. Heinonen O, Slone D, Shapiro S. Birth Defects and Drugs in Pregnancy. Littleton, MA: Publishing Sciences Group, 1977.
41. Wilson F. Congenital defects in the newborn. Br Med J 1962;2:255.
42. Carter MP, Wilson F. Tetracycline and congenital limb abnormalities. Br Med J 1962;2:4078.
43. Mennie AT. Tetracycline and congenital limb abnormalities. Br Med J 1962;2:480.
44. Harley JD, Farrar JF, Gray JB, Dunlop IC. Aromatic drugs and congenital cataracts. Lancet 1964;1:472.
45. Corcoran R, Castles JM. Tetracycline for acne vulgaris and possible teratogenesis. Br Med J 1977;2:8078.
46. Horne HW Jr, Kundsin RB. The role of mycoplasma among 81 consecutive pregnancies: a prospective study. Int J Fertil 1980;25:3157.
47. Coppes JB. Bubonic plague in pregnancy. J Reprod Med 1980;25:915.
48. Czeizel AE, Rockenbauer M. Teratogenic study of doxycycline. Obstet Gynecol 1997;89:5248.
49. Briggs M. Tetracycline and steroid hormone binding to human spermatozoa. Acta Endocrinol 1974;75:78592.
50. Bacon JF, Shenfield GM. Pregnancy attributable to interaction between tetracycline and oral contraceptives. Br Med J 1980;1:283.
51. Knowles JA. Drugs in milk. Pediatr Curr 1972;21:2832.
52. Graf VH, Reimann S. Untersuchungen uber die Konzentration von Pyrrolidino-methyl-tetracycline in der Muttermilch. Dtsch Med Wochenschr 1959;84:1694.
53. Committee on Drugs, American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 1994;93:13750.
    
    

Questions and Answers

Does unprotected sex with YAZ birth control and tetracycline equal pregnant?

Hi all. I have just completed my first month of Yaz birth control pill (today I will take my 3rd pill of the second packet). My period consisted of dark discharge and some very light spotting and it occurred Thursday (last inactive pill) through Friday (first active pill of this packet). I am not sure when I was supposed to expect my period anyway, so I am not sure if that was late or early or what.
Also, here is the catch: I had sex two weeks ago today (on Jan 14) and we used the pull out method (I know i know, unwise...) but i get the sense that my partner accidently let some out because he seemed unusually concerned about whether i was on bcps. To add to the problem, I am currently taking tetracycline, and I am not sure by how much this decreases Yaz's effectiveness and whether or not I should be concerned about the tetracycline. All these factors combined make me incredibly nervous. Sorry for the long question, but I am a little anxious.

Antibiotics decrease the effectivness of bcp. As you already know, the pull out method does not work(my first child is a result of that). I would get a pregnancy test( preferably blood). Being unusually tired can be a symtom of pregnancy. Your period doesnt sound like much of one either, it might not have been.

Your pregnant neighbor has a sore throat and tells you that she is taking some "leftover" tetracycline from a

Your pregnant neighbor has a sore throat and tells you that she is taking some "leftover" tetracycline from a previous infection. Give her two reasons why this is a poor decision. Another woman has been prescribed a broad-spectrum oral cephalosporin for a sore throat. What are some consequences in addition to the cure of the infected throat? Finally, a man has a severe case of gastroenteritis that is negative for bacterial pathogens. A physician prescribes an oral antibiotic. What are your opinions of this therapy?

Throat has to be cultured before the right anti-biotic can be given...always start with a new script...never left over antibiotics.
Man was negative for bacteria so should not be given antibiotics as he needs bacteria in his system ( he would be a prime candidate for C-diff)

Tetracycline is not administered to pregnant women because it accumulates in which of the following, from whic

blood
bone
muscle
skin

Tetracycline is an intracellular bacteriostatic antibiotic that works by binding the 30S ribosomal subunit in bacteria, thereby preventing protein production. However, this antibiotic, and it's sister drug doxycycline, have a tendency to accumulate in the bone leading to discoloration of the teeth and bone fragility. This is especially important in the developing embryo as bone structure is incompletely formed.

Hopefully, this helps more than just answering your homework for you ;)

Yaz birth control, tetracycline, sex, and now no period: Pregnant?

When I completed my first month of Yaz birth control pill , My period consisted of dark discharge and some very light spotting and it occurred Thursday (last inactive pill) through Friday (first active pill of this packet). I am not sure when I was supposed to expect my period, so I am not sure if that was late or early.
Also, here is the catch: I had sex two weeks before that period (on Jan 14) & we used the pull out method (I know it was stupid)but i get the sense that my partner accidently let some out b/c he seemed unusually concerned about whether i was on bcps. Furthermore, I am currently taking tetracycline. I am not sure by how much this decreases Yaz's effectiveness & whether I should be concerned about the tetracycline. NOW i am on last inactive pill of the second month and still no period!! I took 3 hpt last month and they were negative. Should I be worried? i will list other symptoms in additional details

it is true that antibiotics can interfere with the effectiveness of the Pill, so when you take them you should be extra careful when having sex.... like using condoms (which are a heck of a lot cheaper than a pregnancy and everything) or just abstaining. But if you are having gas and discharge and other period symptoms, then it is probably coming. Stress can cause a period to come late, and also that fact that you are just recently starting the pills and your body is adjusting to the hormone levels and that your cycle will change a bit (usually becomes lighter and shorter). If you have continued spotty periods, and you never did before, the hormones might be the wrong levels for you, so ask your doctor for a different brand to try out for three months. If you are still concerned, you can take a blood test...

Taking Antibiotics Before Finding out your pregnant?

Anyone had been taking antibiotics then found out you were pregnant? I am taking Tetracycline (which is known to harm unborn fetus) and there is always a possibility that I may be pregnant. (but I'm probably not--we used protection-just not the whole time tmi-sorry) I'm not due to start until next week but upon reading the cautions on the prescription information sheet I'm a little concerned because of the possibility.

Relax. If you're so early that you can't even test yet, the egg hasn't yet implanted.
Tetracycline can stain/damage the teeth ... but a 1-2 week old embryo dosen't yet HAVE teeth.

Normal for YAZ birth control pills or am I pregnant?

Hi all. I have just completed my first month of Yaz birth control pill (today I will take my 3rd pill of the second packet). My period consisted of dark discharge and some very light spotting and it occurred Thursday (last inactive pill) through Friday (first active pill of this packet). I am not sure when I was supposed to expect my period anyway, so I am not sure if that was late or early or what.
Also, here is the catch: I had sex two weeks ago today (on Jan 14) and we used the pull out method (I know i know, unwise...) but i get the sense that my partner accidently let some out because he seemed unusually concerned about whether i was on bcps. To add to the problem, I am currently taking tetracycline, and I am not sure by how much this decreases Yaz's effectiveness and whether or not I should be concerned about the tetracycline. All these factors combined make me incredibly nervous. Sorry for the long question, but I am a little anxious.

Sweetie, please, please get to your doctor and tell him/her all of this or at LEAST do a home pregnancy test. Whether or not it would be normal to have a period like this on your particular birth control, it is worth the price of a test to either a) have peace of mind or b) know you're pregnant while you still have options.
My best friend in college got pregnant and stayed in denial until she was 5 months along. By that point, there is no good option left to you.
You need to take a pregnancy test, or even better, see your doctor. Good luck and take care of yourself - and make your partners wear rubbers from now on, so you don't have to be scared again, ok? *hugs* I wish you all the best!

Could I be pregnant if I missed two pills in the last week of active pills and had slight bleeding?

I missed two pills in the last week of the active pills and began to slightly bleed after missing the second pill. I had unprotected sex three times during this time and he ejaculated inside me all three times. I am also on a form of tetracycline that I take daily.

I know that this was stupid so please no lectures. Is there a possibility I could become pregnant because of this even though I am bleeding now? And is this bleeding a real period? Has this happened to anyone else? Please only serious answers......Thanks

Not necessarily. It could be whats called breakthrough bleeding, and you wouldn't get pregnant unless you were ovulating at the time you had sex and missed your pills. But yes, Its always a possibility to get pregnant, even when using protection, or being on the pill, even though it is remote, but missing pills and experiencing some bleeding is what sounds like breakthrough bleeding.

Hopefully you are active with the same guy, and not multiple partners...then pregnancy may be the least of your worries.

Good luck