In patients with renal impairment many drugs or their metabolites are excreted more slowly. It is therefore important to know what drugs will require dose reduction or are to be avoided altogether. An exception to this rule is gentamicin where careful use of a nomogram and monitoring of blood levels (peak one (1) hour after i.m. dose and trough before next dose) make its use relatively safe. (see nomogram on p. 21).

Most drugs are conveniently given at an interval equal to the half-life. If a drug is excreted exclusively by the kidney a reduction in Glomerular Filtration Rate (and hence creatinine clearance) will produce a corresponding reduction in drug excretion.

Thus if GFR falls by half the drug half-life can be expected to double; the dosage interval should therefore be doubled, while the loading dose and maintenance dose are not changed.

For practical purposes serum creatinine gives the most useful index of renal function. It does however fall with age and may not reflect the true state in the elderly, who may be assumed to have a GFR of 50ml/min even if serum creatinine is within normal limits.

Displaying 1 - 20 of 235
Drugs to be avoided or used with caution in renal failure
Active Ingredient GFR Dosage recommendations Comments
Acetazolamide 20-50 Avoid Metabolic acidosis
Acyclovir 10-20 - <10 Reduce dose Possible transient
Allopurinol 10-20 100mg daily on alternate days Increased toxicity; rashes 100 mg on alternate days
Alprazolam see Anxiolytics and Hypnotics
Aluminium Salts <10 Aluminium is absorbed and may accumulate. Note: Absorption of aluminium from a More ...
Amantadine 20-50 - 10-20 Reduce dose Excreted by kidney
Amiloride see Potassium-sparing Diuretics
Aminoglycosides 20-50 Reduce dose Monitor plasma concentrations , ototoxic, nephrotoxic
Amoxycillin <10 Reduce dose Rashes more common
Amphotericin 20-50 Use only if no alternative , nephrotoxicity may be reduced with use of complexes
Ampicillin <10 Reduce dose Rashes more common
Analgesics see Opioid Analgesics and NSAIDs
Antipsychotics <10 Start with small doses Increased cerebral sensitivity
Anxiolytics and Hynotics <10 Start with small doses increased cerebral sensitivity
Aspirin <10 Avoid Sodium and water retention ; deteriorationin renal function ; increased risk of More ...
Atenolol see Beta-blockers
Auranofin see Gold
Aurothiomalate see Gold
Azathioprine <10 Reduce dose
Baclofen 20-50 Use smaller doses (e.g) 5 mg daily Excreted by kidney