Medication:
imipramine
tofranil depression
Breastfeeding:
Data taken from Medications and Mothers Milk (Hale 2017 online access).
Relative infant dose quoted as 0.1%–4.4%. Imipramine is metabolised to desip- ramine, the active metabolite. Since the m/p ratio (0.5–1.5) crosses 1, milk levels might be expected to approximate to those of maternal serum. However, 90% is plasma protein bound and unable to pass into breastmilk, so levels in breast- milk may be assumed to be relatively low. The half-life of the drug is 8–16 hours so there is no opportunity to minimise transfer by feeding immediately before taking the drug, even if it has not reached steady state. The low level of trans- fer is borne out by a published case study of two mothers. Ware and DeVane (1990) studied two women taking imipramine 50 mg daily for panic attacks. In one baby, levels of imipramine and desipramine, the active metabolite, were 91 and 185 μm per litre, respectively. In the other, only trace levels were detected.
The m/p ratio is high but a small amount of the drug is free to pass into breastmilk so the absolute level of transferring is limited, reflected in the relative infant dose, which is well below the 10% level taken as safe.
No paediatric side effects have been reported from this drug being taken by a breastfeeding mother, although in theory it could cause the baby to be drowsy and experience a dry mouth. The BNF recommendation is ‘caution in breastfeed- ing, but amounts too small to be harmful’. If the baby exhibited drowsiness or significant weight loss, it should be monitored, or a decision could be made for the mother to stop the drug and see if the baby’s behaviour returned to normal, or, if deemed essential, to formula feed her baby.
Breastfeeding:
Data taken from Medications and Mothers Milk (Hale 2017 online access).
Relative infant dose quoted as 0.1%–4.4%. Imipramine is metabolised to desip- ramine, the active metabolite. Since the m/p ratio (0.5–1.5) crosses 1, milk levels might be expected to approximate to those of maternal serum. However, 90% is plasma protein bound and unable to pass into breastmilk, so levels in breast- milk may be assumed to be relatively low. The half-life of the drug is 8–16 hours so there is no opportunity to minimise transfer by feeding immediately before taking the drug, even if it has not reached steady state. The low level of trans- fer is borne out by a published case study of two mothers. Ware and DeVane (1990) studied two women taking imipramine 50 mg daily for panic attacks. In one baby, levels of imipramine and desipramine, the active metabolite, were 91 and 185 μm per litre, respectively. In the other, only trace levels were detected.
The m/p ratio is high but a small amount of the drug is free to pass into breastmilk so the absolute level of transferring is limited, reflected in the relative infant dose, which is well below the 10% level taken as safe.
No paediatric side effects have been reported from this drug being taken by a breastfeeding mother, although in theory it could cause the baby to be drowsy and experience a dry mouth. The BNF recommendation is ‘caution in breastfeed- ing, but amounts too small to be harmful’. If the baby exhibited drowsiness or significant weight loss, it should be monitored, or a decision could be made for the mother to stop the drug and see if the baby’s behaviour returned to normal, or, if deemed essential, to formula feed her baby.