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Drugs List

  • pivmecillinam 200mg tablets
  • SELEXID 200mg tablets
  • Dosage


    Urinary tract infections:

    Acute uncomplicated cystitis:
    400mg immediately followed by 200mg every 8 hours for 3 days.

    Chronic or recurrent bacteriuria:
    400mg every 6-8 hours.


    Enteric fever:
    1.2 - 2.4 grams daily for 14 days.

    Salmonella carriers:
    1.2 - 2.4 grams daily for 2 - 4 weeks.


    See Dosage; Adults.

    Renal excretion of mecillinam is delayed in the elderly, but significant accumulation of the drug is not likely at the recommended adult dosage of pivmecillinam.


    Contraindicated in infants under 3 months.

    Weight more than 40kg:
    See Dosage; Adults.

    Weight less than 40kg:
    Urinary tract infections:
    20-40mg/kg body weight daily in 3 or 4 divided doses.

    30-60mg/kg body weight daily in 3 or 4 divided doses.

    Patients with Renal Impairment

    High doses may cause convulsions, cerebral irritation or coma.

    Accumulation may occur in patients with severe renal impairment so use the lower dose if using pivmecillinam for an extended period of time.

    In patients with little residual kidney function, pivmecillinam is unlikely to work, as the product works by renal excretion into the bladder, where its site of action is.


    For oral administration.

    Pivmecillinam tablets should be taken with at least half a glass of water to avoid oesophageal ulceration.

    Take preferably with, or immediately after a meal whilst sitting or standing.


    Patients with, or at a predisposition to carnitine deficiency
    Infants under 3 months
    Presence or history of oesophageal strictures and/or obstructive changes in the gastrointestinal tract
    Hypersensitivity to penicillins and/or cephalosporins
    Acute porphyria

    Precautions and Warnings

    Renal impairment - (see Dosage; Renal Impairment). Pivmecillinam is excreted mainly by the kidney, therefore raised blood levels of mecillinam may occur if repeated doses are given to patients with impaired renal function.

    Monitor hepatic and renal function during prolonged therapy.

    Pivmecillinam should be used with caution for long-term or frequently repeated treatment, due to the possibility of carnitine depletion.

    Pivmecillinam can cause false - positive urinary glucose ( if tested for reducing substrates).

    Pregnancy - (see Pregnancy section).

    Breastfeeding - (see Lactation section).

    Use in Porphyria

    Pivmecillinam should be avoided in patients with acute porphyria since it has been associated with acute attacks of porphyria.

    Pregnancy and Lactation


    Pivmecillinam, as mecillinam, crosses the placenta. It is not known to be harmful. Tests in two animal species have shown no teratogenic effects, however the manufacturer advises that use during pregnancy should be avoided.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Pivmecillinam can be used during breastfeeding with no effects on the infant anticipated. Trace quantities of mecillinam are excreted into the breast milk. The possible risks to the infant include modified bowel flora, diarrhoea and allergic responses in a hypersensitive infant.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Effects on Ability to Drive and Operate Machinery

    No effects on the ability to drive or operate machinery have been observed.


    Advise patients to take pivmecillinam tablets with at least half a glass of water, preferably with a meal whilst sitting or standing to avoid oesophageal ulceration.

    Side Effects

    Reduction in serum and in total body carnitine
    Angioneurotic oedema
    Oesophagal ulceration
    Mouth ulceration
    Allergic reactions
    Liver function disorders
    Changes in blood counts (thrombocytopenia, granulocytopenia, leucopenia, eosinophilia)
    Abdominal pain
    Antibiotic associated colitis
    Convulsions (especially in high doses or in severe renal impairment)
    Joint pain
    Interstitial nephritis
    Increases in hepatic enzymes
    Increases in bilirubin
    Gastrointestinal disorders


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Reference Sources

    British National Formulary, 62nd Edition (2011) Pharmaceutical Press, London.

    BNF for Children (2011) Pharmaceutical Press, London.

    Martindale: The Complete Drug Reference, 37th edition (2011) ed. Sweetman, S. Pharmaceutical Press, London.

    The Renal Drug Handbook. 3rd edition. (2009) ed. Ashley, C and Currie, Radcliffe Publishing Ltd, Abingdon.

    Summary of Product Characteristics: Selexid Tablets. Leo Laboratories Ltd. Revised May 2011.

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    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

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    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.