Pivmecillinam

400mg po STAT then 8 hours later 200mg tds

No dose adjustment required

Renal impairment

Dose adjustment is not necessary in impaired renal function.

If using for extended periods of time: Accumulation may occur in patients with severe renal impairment. Discuss with Micro/ID about the need to use a lower dose.

Hepatic impairment

Dose adjustment not necessary

Methotrexate: Pivmecillinam can reduce excretion of methotrexate (increased risk of toxicity).

Valproic acid, valproate or other medication liberating pivalic acid: Avoid concurrent use due to increased risk of carnitine depletion.

Vitamin K antagonists: Appropriate monitoring should be undertaken. It would be prudent to monitor coagulation status within 3 days of starting or stopping a penicillin.

This is not a complete list. Please see the BNF, Summary of Product Characteristics or speak to a pharmacist.

Pregnancy 

Discuss with pharmacy

Breastfeeding 

Safe. Mecillinam is excreted in human milk, but at therapeutic doses of Pivmecillinam no effects on the breast-fed newborns/infants are anticipated. Pivmecillinam can be used during breast-feeding.

Pivmecillinam contra-indications include patients with:

• any condition resulting in impaired transit through the oesophagus (e.g. gastro-intestinal obstruction or oesophageal strictures)
• genetic metabolism anomalies known to be leading to severe carnitine deficiency, such as carnitine transporter defect, methylmalonic aciduria or propionic acidaemia.

This is not a complete list. Please see the BNF, SPC or speak to a pharmacist.

Pivmecillinam should be used with caution in patients with porphyria since pivmecillinam has been associated with acute attacks of porphyria.

The intake of pivmecillinam shortly before delivery may cause a false positive test for isovaleric acidemia in the newborn as part of neonatal screening. 

• Aurobindo Pharma - Milpharm Ltd. Pivmecillinam 200mg film-coated tablets summary of product characteristics: Electronic Medicines Compendium [Internet]. Last revision of the text: 26/10/2023. Accessed 14/12/23 from https://www.medicines.org.uk/emc/product/4982/smpc 
• Karo Pharma AB. Selexid Tablets summary of product characteristics: Electronic Medicines Compendium [Internet]. Last revision of the text: 07/03/2023. Accessed 14/12/23 from https://www.medicines.org.uk/emc/product/3799/smp 
• Joint Formulary Committee. British National Formulary (BNF). 27 September 2023 [Internet]. .Accessed 14/12/23 fromhttps://www.medicinescomplete.com 
• Meng L, Mui E, Ha DR, Stave C, Deresinski SC, Holubar M. Comprehensive guidance for antibiotic dosing in obese adults: 2022 update. Pharmacotherapy. 2023; 43(3):226-46
• The Renal Drug Database. Pivmecillinam Hydrochloride [Internet]. Revision date 22/5/23. Accessed 14/12/23 at: https://renaldrugdatabase.com/monographs/pivmecillinam-hydrochloride 
• UK Teratology Information Service. Use of penicillins in pregnancy [Internet]. January 2019 [cited 2023 Oct 12]. Available from: https://uktis.org/monographs/use-of-penicillins-in-pregnancy/ 
• The Breastfeeding Network, Antibiotics and Breastfeeding [Internet]. October 2022 [cited 2023 Nov 20]. Available from: https://www.breastfeedingnetwork.org.uk/factsheet/antibiotics/
• Specialist Pharmacy Service. Pivmecillinam – Lactation Safety Information [Internet]. Revision date 21 September 2020 [cited Oct 12]. Available from: https://www.sps.nhs.uk/medicines/pivmecillinam/