Cimetidine

DRUG INFORMATION

  ADULT
    - In a U.S. dose-ranging study of 400 mg at bedtime, 800 mg at bedtime and 1,600 mg
      at bedtime, a continuous dose-response relationship for ulcer healing was
      demonstrated.
      Source: US FDA label for cimetidine (Cimetidine), section 'dosage and
      administration', retrieved 2026-08-29
    - However, 800 mg at bedtime is the dose of choice for most patients, as it provides
      a high healing rate (the difference between 800 mg at bedtime and 1,600 mg at
      bedtime being small), maximal pain relief, a decreased potential for drug
      interactions (see PRECAUTIONS: Drug Interactions ) and maximal patient
      convenience.
      Source: US FDA label for cimetidine (Cimetidine), section 'dosage and
      administration', retrieved 2026-08-29
    - There is some evidence which suggests that more rapid healing can be achieved in
      this subpopulation with 1,600 mg of cimetidine tablets at bedtime.
      Source: US FDA label for cimetidine (Cimetidine), section 'dosage and
      administration', retrieved 2026-08-29

  CHILD
    - Clinical experience in children is limited. Therefore, therapy with cimetidine
      cannot be recommended for children under 16, unless, in the judgement of the
      physician, anticipated benefits outweigh the potential risks. In very limited
      experience, doses of 20 mg/kg/day to 40 mg/kg/day have been used.
      Source: US FDA label for cimetidine (Cimetidine), section 'pediatric use',
      retrieved 2026-08-29
    - In very limited experience, doses of 20 mg/kg/day to 40 mg/kg/day have been used.
      Source: US FDA label for cimetidine (Cimetidine), section 'pediatric use',
      retrieved 2026-08-29

  RENAL IMPAIRMENT
    - No kidney-impairment dose in this label. Not a statement that none is needed.
      Source: Read and found silent: the US FDA label for cimetidine (Cimetidine),
      retrieved 2026-08-29

  HEPATIC IMPAIRMENT
    - When liver impairment is also present, further reductions in dosage may be
      necessary.
      Source: US FDA label for cimetidine (Cimetidine), section 'dosage and
      administration', retrieved 2026-08-29

  PREGNANCY   [ CAUTION ]
    The label allows it only when the benefit is judged to outweigh the risk. Read the
      quote below.
    - Reproduction studies have been performed in rats, rabbits and mice at doses up to
      40 times the normal human dose and have revealed no evidence of impaired fertility
      or harm to the fetus due to cimetidine.
      Source: US FDA label for cimetidine (Cimetidine), section 'pregnancy', retrieved
      2026-08-29
    - There are, however, no adequate and well-controlled studies in pregnant women.
      Source: US FDA label for cimetidine (Cimetidine), section 'pregnancy', retrieved
      2026-08-29
    - Because animal reproductive studies are not always predictive of human response,
      this drug should be used during pregnancy only if clearly needed.
      Source: US FDA label for cimetidine (Cimetidine), section 'pregnancy', retrieved
      2026-08-29

  BREASTFEEDING
    - Cimetidine is secreted in human milk and, as a general rule, nursing should not be
      undertaken while a patient is on a drug.
      Source: US FDA label for cimetidine (Cimetidine), section 'nursing mothers',
      retrieved 2026-08-29