Animal studies have revealed evidence of embryofetal toxicity with higher doses. Delayed skeletal ossification, decreased fetal body weight, and increased postimplantation loss in rats and rabbits, plus abortion in rabbits, were observed with doses about 8.6-times (rats) and 6.3-times (rabbits) the clinical exposure (based on AUC); no treatment-related effects observed with doses about 3-times (rats) and 2.8-times (rabbits) the clinical exposure (based on AUC) administered during organogenesis. Animal studies indicate this drug crosses the placenta and is found in fetal plasma. There are no controlled data in human pregnancy.

Based on animal studies, this drug can cause impaired spermiation and sperm maturation, which results in abnormal sperm morphology and poor motility. The effect is reversible in rats. The long-term effects of this drug on male fertility have not been studied.

US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

Use is not recommended unless clearly needed.

US FDA pregnancy category: Not assigned.

Risk summary: Insufficient data available on use of this drug in pregnant women to inform a drug-related risk.

Comments:
-Use of tetracycline-class antibacterial agents (including this drug) during the second and third trimester of pregnancy may cause permanent dental defects (discoloration of deciduous teeth and enamel defects) and reversible inhibition of bone growth.
-If this drug is used during the second or third trimester of pregnancy, the patient should be apprised of the potential harm to the fetus.
-Patients of childbearing potential should avoid becoming pregnant while receiving this drug.

See references

Short-term use is considered acceptable; as a precaution, prolonged or repeat courses should be avoided during breastfeeding.
-According to some authorities: Breastfeeding is not recommended during use of this drug and for 4 days after the last dose.
-According to some authorities: A decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother and the benefit of breastfeeding for the child.

Excreted into human milk: Unknown
Excreted into animal milk: Yes (including metabolites)

Comments:
-No information is available on the use of this drug during breastfeeding.
-The effects in the nursing infant are unknown.
-Tetracyclines are excreted into human milk; extent of absorption of tetracyclines (including this drug) by nursing infants not known.
-Patients should be advised not to breastfeed during therapy and for 4 days after the last dose because other antibacterial agents are available to treat nursing women and due to the potential for serious side effects (including tooth discoloration, inhibition of bone growth).
-If an infant is breastfed, the infant should be monitored for possible effects on the gastrointestinal flora (e.g., diarrhea, candidiasis [e.g., thrush, diaper rash], blood in stool [indicating possible antibiotic-associated colitis]).

According to available literature, there is not likely to be harm in short-term use of this drug during nursing because the drug is 79% to 90% bound to plasma proteins; milk levels are likely low and absorption by the infant is likely inhibited by the calcium in breast milk.

Long-term use of other tetracyclines during breastfeeding may result in significant absorption by the breastfed infant. Long-term use is not recommended due to the risk of dental discoloration and delay in ossification processes of the nursing infant.

See references