Authors: Dr. Sunira Chandra, Dr. Kunal Sah, Department of Oral Medicine & Radiology, Teerthankar Mahaveer Dental College & Research Centre

Abstract
Most of the dentists prescribe drugs to nursing mothers. But only few, knows its pharmacokinetics adverse affects to fetus. Dentist should be very causious before prescribing any drug to the nursing mothers. Prescription of various contraindicated drugs to nursing mothers can compromise baby growth, their intellectual ability and in some cases even causes death. This paper review various contraindicated drugs or drugs having various adverse effects and should be not given to nursing mother.

Key words: Drugs, nursing mother, contraindications

PRESCRIBING DRUGS TO BREAST FEEDING PATIENTS: DENTIST BE CAUTIOUS!

Introduction

Breast milk is the nutrition of choice newborns. The American Academy of Pediatrics recommends exclusive breastfeeding for a minimum of 6 month and introduction of appropriate solid food from 6 month to 1 year. Beyond 1 year, breastfeeding continues for as long as both infant and mother desire, although after 1 year, breastfeeding should complement a full diet of solid foods and fluids.

Breast feeding patient presents a number of unique management problems for oral health care providers. Cli­nicians are responsible for provid­ing safe and effective care for the mother, while also considering the safety of the fetus or newborn. They must consider the effects of medications, which may be distributed from the maternal plasma through the placenta to the fetus, or to breast milk, exposing the nursing infant to potentially dan­gero us concentrations. This article summarizes various drugs which are contraindicated during breastfeeding or have some adverse effect on nursing infants.

Passage of drugs from plasma to milk

With the increasing recognition of the benefits of breast-feeding, cli­nicians must often weigh the ben­efits versus risks of drug therapy in lactating women. The rate of pas­sage of a drug from plasma to milk is an important determinant of the concentration of the drug in milk. Mechanisms of excretion of drugs in breast milk include both passive diffusion and carrier-me­diated transport.
The amount of a drug excreted in breast milk de­pends on the characteristics of the drug, such as the drug's molecu­lar weight, lipid solubility, pKa, and plasma protein binding. Small, water-soluble non electro­lytes pass into milk by simple diffu­sion through aqueous channels in the mammary epithelial mem­brane that separates plasma from milk. Equilibrium is reached rap­idly, and the drug's concentration in milk approximates plasma lev­els. With larger molecules, only the lipid soluble, nonionized form passes through the membrane.
The pKa of weak electrolytes is an important determinant of drug concentration in milk, because the pH of milk is generally lower (more acidic) than that of plasma, and milk can act as an "ion trap" for weak bases. At equilibrium, basic drugs may be more concen­trated in milk relative to plasma. Conversely, acidic drugs are lim­ited in their ability to enter milk, because the concentration of nonionized free form in milk is higher than in plasma, and a net transfer of the drug from milk to plasma occurs.

Drug therapy for breast feeding patient

The following should be considered before prescribing drugs to lactating women:

• Is drug therapy really necessary? If drugs are required, consultation between the pediatrician and the mother’s physician can be most useful in determining what options to choose.
• The safest drug should be chosen, for example, acetaminophen rather than aspirin for analgesia.
• If there is a possibility that a drug may present a risk to the infant, consideration should be given to measurement of blood concentrations in the nursing infant.
• Drug exposure to the nursing infant may be minimized by having the mother take the medication just after she has breastfed the infant or just before the infant is due to have a lengthy sleep period.

The American Academy of Pediatrics published guidelines and a classification system for drugs used in lactating women.

The American Academy of Pediatrics: Classification System
ND : No data available
C : Compatible with breastfeeding
CC : Compatible with breastfeeding but use caution
SD : Strongly discouraged in breastfeeding
X : Contraindicated in breastfeeding

These classifications are based on controlled studies in animals or humans and on data gathered from using the drugs in pregnant women. Most medications fall into the category "No data available."

A statement on the transfer of drugs and chemicals into human milk was first published in1983, with revisions in 1989 and 1994. Information continues to become available. The current statement is intended to revise the lists of agents transferred into human milk and describe their possible effects on the infant or on lactation, if known (Tables 1–6). If a pharmacologic or chemical agent does not appear in the tables, it does not mean that it is not transferred into human milk or that it does not have an effect on the infant; it only indicates that there were no reports found in the literature. These tables should assist the physician in counseling a nursing mother regarding breastfeeding when the mother has a condition for which a drug is medically indicated.

Conclusion

Dentist should be very causious before prescribing any drug to the nursing mothers. Prescription of various contraindicated drugs to breastfeeding mothers can compromise baby growth, their intellectual ability and in some cases even causes death.The clinician's primary goal should be to provide necessary care for the patient while minimizing the risk to her newborn. Prior to the initiation of dental treatment or when complications arise during care, a consultation with the patient's obstetrician is always re­quired.

TABLE 1: CYTOTOXIC DRUGS THAT MAY INTERFERE WITH CELLULAR METABOLISM OF THE NURSING INFANT

Drugs	Reason for Concern, Reported Sign or Symptom in Infant, or Effect on Lactation
Cyclophosphamide	Possible immune suppression; unknown effect on growth or association with carcinogenesis; neutropenia
Cyclosporine	Possible immune suppression; unknown effect on growth or association with carcinogenesis
Doxorubicin	Possible immune suppression; unknown effect on growth association with carcinogenesis
Methotrexate	Possible immune suppression; unknown effect on growth or association with carcinogenesis; neutropenia

TABLE 2: DRUGS OF ABUSE FOR WHICH ADVERSE EFFECTS ON THE INFANT DURING BREASTFEEDING HAVE BEEN REPORTED

Drugs	Reported Effect or Reasons for Concern
Amphetamine	Irritability, poor sleeping pattern
Cocaine	Cocaine intoxication: irritability, vomiting, diarrhea, tremulousness, seizures
Heroin	Tremors, restlessness, vomiting, poor feeding
Phencyclidine	Potent hallucinogen

TABLE 3: RADIOACTIVE COMPOUNDS THAT REQUIRE TEMPORARY CESSATION OF BREASTFEEDING

Compound	Recommended Time for Cessation of Breastfeeding
Copper 64	Radioactivity in milk present at 50 h
Gallium 67	Radioactivity in milk present for 2 wk
Indium 111	Very small amount present at 20 h
Iodine 123	Radioactivity in milk present up to 36 h
Iodine 125	Radioactivity in milk present for 12 d
Iodine 131	Radioactivity in milk present 2–14 d

TABLE 4: DRUGS FOR WHICH THE EFFECT ON NURSING INFANTS IS UNKNOWN BUT MAY BE OF CONCERN

Drugs	Reported or Possible Effect
Anti-anxiety Drugs Alprazolam Diazepam Lorazepam Midazolam Perphenazine Prazepam Quazepam Temazepam
Antidepressants Drugs Amitriptyline Amoxapine Bupropion Clomipramine Desipramine Dothiepin Doxepin Fluoxetine Fluvoxamine Imipramine Nortriptyline Paroxetine Sertraline Trazodone	Colic, irritability, feeding and sleep disorders, slow weight gain
Antipsychotic Drugs Chlorpromazine Chlorprothixene Clozapine Haloperidol Mesoridazine Trifluoperazine	Galactorrhea in mother; drowsiness and lethargy in infant; decline in developmental scores Decline in developmental scores
Others Amiodarone Chloramphenico Clofazimine Lamotrigine Metoclopramide Metronidazole Tinidazole	Possible hypothyroidism Possible idiosyncratic bone marrow suppression Potential for transfer of high percentage of maternal dose; possible increase in skin pigmentation Potential therapeutic serum concentrations in infant None described; dopaminergic blocking agent In vitro mutagen; may discontinue breastfeeding for 12–24 h to allow excretion of dose when single-dose therapy given to mother See metronidazole

Psychotropic drugs, the compounds listed under anti-anxiety, antidepressant, and antipsychotic categories, are of special concern when given to nursing mothers for long periods. Although there are very few case reports of adverse effects in breastfeeding infants, these drugs do appear in human milk and, thus, could conceivably alter short-term and long-term central nervous system function.

TABLE 5: DRUGS THAT HAVE BEEN ASSOCIATED WITH SIGNIFICANT EFFECTS ON SOME NURSING INFANTS AND SHOULD BE GIVEN TO NURSING MOTHERS WITH CAUTION

Drugs	Reported Effect
Acebutolol	Hypotension; bradycardia; tachypnea
5-Aminosalicylic acid	Diarrhea
Atenolol	Cyanosis; bradycardia
Bromocriptine	Suppresses lactation; may be hazardous to the mother
Aspirin (salicylates)	Metabolic acidosis
Clemastine	Drowsiness, irritability, refusal to feed, high-pitched cry, neck stiffness
Ergotamine	Vomiting, diarrhea, convulsions (doses used in migraine medications)
Lithium	One-third to one-half therapeutic blood concentration in infants
Phenindione	Anticoagulant: can increased prothrombin and partial thromboplastin time
Phenobarbital	Sedation; infantile spasms after weaning from milk containing phenobarbital, methemoglobinemia
Primidone	Sedation, feeding problems

Blood concentration in the infant may be of clinical importance.

TABLE 6: FOOD AND ENVIRONMENTAL AGENTS: EFFECTS ON BREASTFEEDING

Agents	Reported Sign or Symptom in Infant or Effect on Lactation
Aspartame	Caution if mother or infant has phenylketonuria
Chocolate (theobromine)	Irritability or increased bowel activity if excess amounts (16 oz/d) consumed by mother
Fava beans	Hemolysis in patient with G-6-PD deficiency
Hexachlorobenzene	Skin rash, diarrhea, vomiting, dark urine, neurotoxicity, death
Lead	Possible neurotoxicity
Mercury, methylmercury	May affect neurodevelopment
Silicone	Esophageal dysmotility
Tetrachloroethylene cleaning fluid (perchloroethylene)	Obstructive jaundice, dark urine

References

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• American Academy of Pediatrics, Committee on Drugs. The transfer of drugs and other chemicals into human milk. Pediatrics. 1989; 84:924–936.
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