20 to 50     : Dose as in normal renal function
10 to 20     : Dose as in normal renal function
<10           : Dose as in normal renal function
DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES
CAPD                : Not dialysed. Dose as in normal renal function
HD                     : Not dialysed. Dose as in normal renal function
HDF/high flux   : Unknown dialysability. Dose as in normal renal function
CAV/VVHD      : Unknown dialysability. Dose as in normal renal function
IMPORTANT DRUG INTERACTIONS
Potentially hazardous interactions with other drugs
Alcohol: increased sedative effect
Analgesics: increased risk of CNS toxicity with tramadol; possibly increased risk of side effects with nefopam; possibly increased sedative effects with opioids
Anti-arrhythmics: increased risk of ventricular arrhythmias with amiodarone – avoid concomitant use; increased risk of ventricular arrhythmias with drugs that prolong the QT interval; increased risk of arrhythmias with propafenone
Antibacterials: increased risk of ventricular arrhythmias with moxifloxacin – avoid concomitant use; concentration reduced by rifampicin
Anticoagulants: may alter anticoagulant effect of coumarins
Antidepressants: enhanced CNS excitation and hypertension with MAOIs and moclobemide – avoid concomitant use; concentration possibly increased with SSRIs
Anti-epileptics: convulsive threshold lowered; concentration reduced by carbamazepine, primidone, barbiturates and possibly phenytoin
Antimalarials: avoid concomitant use with artemether/lumefantrine
Antipsychotics: increased risk of ventricular arrhythmias especially with pimozide; increased antimuscarinic effects with clozapine and phenothiazines; concentration increased by antipsychotics
Antivirals: increased tricyclic side effects with amprenavir; concentration possibly increased with ritonavir
Atomoxetine: increased risk of ventricular arrhythmias and possibly convulsions
Beta-blockers: increased risk of ventricular arrhythmias with sotalol
Clonidine: tricyclics antagonise hypotensive effect; increased risk of hypertension on clonidine withdrawal
Dopaminergics: avoid use with entacapone; CNS toxicity reported with selegiline and rasagiline
Pentamidine: increased risk of ventricular arrhythmias
Sibutramine: increased risk of CNS toxicity – avoid concomitant use
Sympathomimetics: increased risk of hypertension and arrhythmias with adrenaline and noradrenaline; metabolism possibly inhibited by methylphenidate