- Drugs which inc QT interval
- Other antidepressants: tricyclics plus trazodone and venlafaxine.
- Antibiotics:
- Macrolides (erythromycin, clarithromycin, azithromycin).
- Ampicillin.
- Co-trimoxazole.
- Quinolones (ciprofloxacin, levofloxacin, norfloxacin, moxifloxacin).
- Antiarrhythmics including amiodarone, dronedarone, sotalol and quinidine.
- Antipsychotics: all antipsychotics, but highest risk with haloperidol and pimozide.
- Lithium, with greater risk if lithium levels are raised.
- Methadone, especially doses above 100mg.
- Antimalarials: mefloquine, chloroquine, artemether/lumefantrine.
- Quinine: especially at higher doses.
- Azoles: including fluconazole.
- Antihistamines: particularly astemizole and mizolastine.
- Discuss choice of antidepressant, covering:
- anticipated adverse events – for example, side effects and discontinuation symptoms (see stopping or reducing antidepressants).
- potential interactions with concomitant medication or physical illness2
- Normally choose an SSRI in generic form. Take the following into account:
- SSRIs are associated with an increased risk of bleeding. Consider prescribing a gastroprotective drug in older people who are taking NSAIDs or aspirin.
- Fluoxetine, fluvoxamine and paroxetine have a higher propensity for drug interactions2.
- For people who also have a chronic physical health problem, consider using citalopram or sertraline as these have a lower propensity for interactions.
- Paroxetine is associated with a higher incidence of discontinuation symptoms.
- Take into account toxicity in overdose for people at significant risk of suicide. Be aware that:
- compared with other equally effective antidepressants recommended in primary care, venlafaxine is associated with a greater risk of death from overdose
- the greatest risk in overdose is with TCAs, except for lofepramine.
- When prescribing drugs other than SSRIs, take into account:
- the increased likelihood of the person stopping treatment because of side effects, and the consequent need to increase the dose gradually, with venlafaxine, duloxetine and TCAs
- the specific cautions, contraindications and monitoring requirements for some drugs2
- that non-reversible MAOIs, such as phenelzine, combined antidepressants and lithium augmentation of antidepressants should normally be prescribed only by specialist mental health professionals (for more information see sequencing treatments).
- that dosulepin should not be prescribed.
- When prescribing antidepressants for older adults:
- prescribe at an age-appropriate dose taking into account physical health and concomitant medication
- monitor carefully for side effects.
(Cochrane 2008, CD 000448)
