Chemical formula: C₁₇H₁₇NO₂ Molecular mass: 267.322 g/mol PubChem compound: 6005
Apomorphine interacts in the following cases:
Apomorphine may cause modest prolongation of the QTc interval. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. In addition, some of these agents (e.g., phenothiazines, tricyclic antidepressants) may cause additive sedative and hypotensive effects with apomorphine.
Coadministration with dopamine antagonists (e.g., neuroleptic agents, metoclopramide) may decrease the effectiveness of apomorphine, which is a dopaminergic agent. In addition, some of these agents as well as apomorphine have been associated with sedation, hypotension, and QT interval prolongation. Additive pharmacodynamic effects may occur when used in combination. Excessive prolongation of the QT interval can increase the risk of ventricular arrhythmias including torsade de pointes and sudden death in susceptible patients.
Central nervous system (CNS) depressant effects may be additively or synergistically increased in patients using apomorphine in combination with other drugs that can also cause these effects. Apomorphine alone has been frequently associated with somnolence and dizziness. Patients may suddenly fall asleep during activities of daily living.
The use of other sedating drugs should generally be avoided during apomorphine treatment. Patients prescribed these agents concurrently should be monitored for potentially excessive or prolonged CNS depression, especially if they are elderly or debilitated. Ambulatory patients should be made aware of the possibility of additive CNS effects (e.g., drowsiness, dizziness, lightheadedness, confusion) and counseled to avoid activities requiring mental alertness until they know how these agents affect them. If patients experience increased episodes of falling asleep during normal daily activities, they should avoid driving and other potentially hazardous activities until they have contacted their physician.
Since apomorphine, especially at high dose, may have the potential for QT prolongation, caution should be exercised when treating patients at risk for torsades de pointes arrhythmia.
Neuroleptic medicinal products may have an antagonistic effect if used with apomorphine. There is a potential interaction between clozapine and apomorphine, however clozapine may also be used to reduce the symptoms of neuropsychiatric complications.
When used in combination with domperidone, risk factors in the individual patient should be carefully assessed. This should be done before treatment initiation, and during treatment. Important risk factors include serious underlying heart conditions such as congestive cardiac failure, severe hepatic impairment or significant electrolyte disturbance.
Since apomorphine may produce hypotension, even when given with domperidone pre-treatment, care should be exercised in patients with pre-existing cardiac disease or in patients taking vasoactive medicinal products such as anti-hypertensives, and especially in patients with pre-existing postural hypotension.
An ECG should be performed prior to treatment with domperidone.
Toremifene has the potential to prolong the QT interval of the electrocardiogram in some patients. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia).
There is no experience of apomorphine usage in pregnant women.
Animal reproduction studies do not indicate any teratogenic effects, but doses given to rats which are toxic to the mother can lead to failure to breathe in the newborn. The potential risk for humans is unknown.
Apomorphine should not be used during pregnancy unless clearly necessary.
It is not known whether apomorphine is excreted in breast milk. A decision on whether to continue/discontinue breastfeeding or to continue/discontinue therapy with apomorphine should be made taking into account the benefit of breast-feeding to the child and the benefit of apomorphine to the woman.
Apomorphine has minor or moderate influence on the ability to drive and use machines.
Patients being treated with apomorphine and presenting with somnolence and/or sudden sleep episodes must be informed to refrain from driving or engaging in activities (e.g. operating machines) where impaired alertness may put themselves or others at risk of serious injury or death until such recurrent episodes and somnolence have resolved.
This medicine can impair cognitive function and can affect a patient’s ability to drive safely. This class of medicine is in the list of drugs included in regulations under 5a of the Road Traffic Act 1988. When prescribing this medicine, patients should be told:
Very common (≥1/10)
Common (≥1/100 to <1/10)
Uncommon (≥1/1,000 to <1/100)
Rare (≥1/10,000 to <1/1,000)
Very rare (<1/10,000)
Not known (cannot be estimated from the available data)
Uncommon: Haemolytic anaemia and thrombocytopenia have been reported in patients treated with apomorphine.
Rare: Eosinophilia has rarely occurred during treatment with apomorphine HCl.
Rare: Due to the presence of sodium bisulphite, allergic reactions (including anaphylaxis and bronchospasm) may occur.
Very Common: Hallucinations
Common: Neuropsychiatric disturbances (including transient mild confusion and visual hallucinations) have occurred during apomorphine HCl therapy.
Not known: Impulse control disorders: Pathological gambling, increased libido, hypersexuality, compulsive spending or buying, binge eating and compulsive eating can occur in patients treated with dopamine agonists including apomorphine. Aggression, agitation.
Common: Transient sedation with each dose of apomorphine HCl at the start of therapy may occur; this usually resolves over the first few weeks. Apomorphine is associated with somnolence. Dizziness/light-headedness have also been reported.
Uncommon: Apomorphine may induce dyskinesias during ‘on’ periods, which can be severe in some cases, and in a few patients may result in cessation of therapy.
Apomorphine has been associated with sudden sleep onset episodes.
Not known: Syncope, Headache
Uncommon: Postural hypotension is seen infrequently and is usually transient.
Common: Yawning has been reported during apomorphine therapy.
Uncommon: Breathing difficulties have been reported.
Common: Nausea and vomiting, particularly when apomorphine treatment is first initiated, usually as a result of the omission of domperidone.
Uncommon: Local and generalised rashes have been reported.
Very common: Most patients experience injection site reactions, particularly with continuous use. These may include subcutaneous nodules, induration, erythema, tenderness and panniculitis. Various other local reactions (such as irritation, itching, bruising and pain) may also occur.
Uncommon: Injection site necrosis and ulceration have been reported.
Not known: Peripheral oedema has been reported.
Uncommon: Positive Coombs' tests have been reported for patients receiving apomorphine.
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