Drugs, Pregnancy & Lactation

Breastfeeding with the FDA’s novel drugs approved in 2017, and others


The use of only one 2017 novel drug (Benznidazole) during breastfeeding has been reported. No reports describing the use of the other drugs while breastfeeding have been located. Nevertheless, exposure of a nursing infant should be considered if the mother is taking any of these drugs.

During the first 2 days after birth, nearly all drugs will be excreted into milk, but the amounts are very small and will probably have no effect on the nursing infant. After the second day, drugs with molecular weights of less than 1,000 g/mol will be excreted into milk. Some drugs with high molecular weights may also be excreted, but they may be digested in the infant’s gut. If a mother is receiving one of the drugs below and is breastfeeding, her infant should be monitored for the most common adverse effects, shown below, that were observed in nonpregnant adults.

Gerald G. Briggs, clinical professor of pharmacy at the University of California, San Francisco, and adjunct professor of pharmacy at the University of Southern California, Los Angeles, as well as at Washington State University, Spokane

Gerald G. Briggs


Benznidazole (MW 260 g/mol). Abdominal pain, rash, decreased weight, headache, nausea, vomiting, neutropenia, urticaria, pruritus, eosinophilia, decreased appetite.

Delafloxacin (Baxdela) (MW 441 g/mol). Nausea, diarrhea, headache, transaminase elevations, vomiting.

Glecaprevir / Pibrentasvir (Mavyret) (MWs 839, 1,113 g/mol). Headache, fatigue.

Letermovir (Prevymis) (MW 573 g/mol). Nausea, vomiting, diarrhea, peripheral edema, cough, headache, fatigue, abdominal pain.

Meropenem / vaborbactam (Vabomere) (MWs 438, 297 g/mol). Headache, diarrhea.

Ozenoxacin cream (Xepi) (MW 363 g/mol). No relevant adverse reactions.

Sofosbuvir / Velpatasvir / Voxilaprevir (Vosevi) (MWs 529, 883, 869 g/mol). Headache, fatigue, diarrhea, nausea.

Secnidazole (Solosec) (MW 185 g/mol). Headache, nausea, dysgeusia, vomiting, diarrhea, abdominal pain. Manufacturer recommends discontinuing breastfeeding for 96 hours after administration of the drug.


[Note: All of the drugs in this category are best avoided, if possible, when breastfeeding.]

Abemaciclib (Verzenio) (MW 507 g/mol). Diarrhea, neutropenia, nausea, vomiting, abdominal pain, infections, fatigue, anemia, leukopenia, decreased appetite, headache, alopecia, thrombocytopenia.

Acalabrutinib (Calquence) (MW 466 g/mol). Anemia, thrombocytopenia, headache, neutropenia, diarrhea, myalgia, bruising.

Avelumab (Bavencio) (MW 147 kg/mol). Fatigue, musculoskeletal pain, diarrhea, nausea, rash, decreased appetite, peripheral edema, urinary tract infection.

Brigatinib (Alunbrig) (MW 584 g/mol). Nausea, fatigue, cough, headache.

Copanlisib (Aliqopa) (MW 480 g/mol). Hyperglycemia, diarrhea, decreased strength and energy, hypertension, leukopenia, neutropenia, nausea, lower respiratory infections, thrombocytopenia.

Durvalumab (Imfinzi) (MW 146 kg/mol). Fatigue, musculoskeletal pain, constipation, decreased appetite, nausea, peripheral edema, urinary tract infections, cough, upper respiratory tract infections, dyspnea, rash.

Enasidenib mesylate (Idhifa) (MW 569 g/mol). Nausea, vomiting, diarrhea, elevated bilirubin, decreased appetite.

Inotuzumab ozogamicin (Besponsa) (MW 160 kg/mol). Thrombocytopenia, neutropenia, anemia, leukopenia, fatigue, hemorrhage, pyrexia, nausea, headache, febrile neutropenia, transaminases increased, abdominal pain, increased gamma-glutamyltransferase, and hyperbilirubinemia.

Midostaurin (Rydapt) (MW 571 g/mol). Febrile neutropenia, nausea, mucositis, vomiting, headache, petechiae, musculoskeletal pain, epistaxis, hyperglycemia, vomiting, diarrhea, edema, pyrexia, dyspnea.

Neratinib (Nerlynx) (MW 557 g/mol). Diarrhea, nausea, vomiting, abdominal pain, fatigue, rash, stomatitis, decreased appetite, muscle spasms, dyspepsia, nail disorder, dry skin, abdominal distention, decreased weight, urinary tract infection.

Niraparib (Zejula) (MW 511 g/mol). Thrombocytopenia, anemia, neutropenia, leukopenia, palpitations, nausea, vomiting, constipation, abdominal pain/distention, mucositis/stomatitis, diarrhea, dry mouth, fatigue/asthenia, decreased appetite, urinary tract infection, myalgia, back pain, arthralgia, headache, dizziness, dysgeusia, insomnia, anxiety, nasopharyngitis, dyspnea, cough, rash, hypertension.

Ribociclib (Kisqali) (MW 553 g/mol). Neutropenia, nausea, fatigue, diarrhea, leukopenia, alopecia, vomiting, constipation, headache, back pain.


Angiotensin II (Giapreza) (MW 1,046 g/mol). Thromboembolic events.

Central nervous system

Deutetrabenazine (Austedo) (MW 324 g/mol). Somnolence, diarrhea, dry mouth, fatigue, nasopharyngitis.

Edaravone (Radicava) (MW 174 g/mol). Confusion, gait disturbance, headache.

Naldemedine (Symproic) (MW 743 g/mol). Abdominal pain, diarrhea, nausea, gastroenteritis.

Ocrelizumab (Ocrevus) (MW 145 kg/mol). Upper and lower respiratory tract infections.

Safinamide (Xadago) (MW 399 g/mol). Dyskinesia, fall, nausea, insomnia.

Valbenazine (Ingrezza) (MW 419 g/mol). Somnolence.


Brodalumab (Siliq) (MW 144 kg/mol). Arthralgia, headache, fatigue, diarrhea, oropharyngeal pain, nausea, myalgia, influenza, neutropenia, tinea infections.

Dupilumab (Dupixent) (MW 146.9 kg/mol). Conjunctivitis, blepharitis, oral herpes, keratitis, eye pruritus, other herpes simplex virus infection, dry eye.

Guselkumab (Tremfya) (MW 143.6 kg/mol). Upper respiratory infections, headache, arthralgia, diarrhea, gastroenteritis, tinea infections, herpes simplex infections.

Endocrine / metabolic

Deflazacort (Emflaza) (MW 442 g/mol). Cushingoid appearance, weight increased, increased appetite, upper respiratory tract infection, cough, pollakiuria, hirsutism, central obesity, nasopharyngitis.

Ertugliflozin (Steglatro) (MW 566 g/mol). Female genital mycotic infections.

Etelcalcetide (Parsabiv) (MW 1,048 g/mol). Blood calcium decreased, muscle spasms, diarrhea, nausea, vomiting, headache, hypocalcemia, paresthesia.

Macimorelin (Macrilen) (MW 535 g/mol). Dysgeusia, dizziness, headache, fatigue, nausea, hunger, diarrhea, upper respiratory tract infection, feeling hot, hyperhidrosis, nasopharyngitis, sinus bradycardia.

Semaglutide (Ozempic) (MW 4,114 g/mol). Nausea, vomiting, diarrhea, abdominal pain, constipation.

Vestronidase alfa (Mepsevii) (MW 72.5 kg/mol). Diarrhea, rash, anaphylaxis, pruritus.


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