APOMORPHINE HYDROCHLORIDE
| APOMORPHINE HYDROCHLORIDE (a-po-mor'feen) Apokyn Classifications: antiparkinson agent; dopamine receptor agonist; Therapeutic:antiparkinson agent Pregnancy Category: C |
Availability
10 mg/mL injection
Action
Apomorphine has central dopamine receptor agonist properties. Its mechanism of action in treatment of Parkinson's is thought to be related to its stimulation of centrally located postsynaptic dopamine D2-type receptors.
Therapeutic Effect
Diminishes hypomobility associated with "off" episodes ("end-of-dose wearing off" and unpredictable "on/off" episodes) in persons with advanced Parkinson's disease.
Uses
Rescue of "off" episodes associated with advanced Parkinson's disease.
Contraindications
Concomitant use of drugs of the 5-HT3 antagonist class (e.g., ondansetron, granisetron, dolasetron, palonosetron, and alosetron); hypersensitivity to the drug or its ingredients (i.e., sodium metabisulfite), benzyl alcohol hypersensitivity; renal failure; QT prolongation; heart failure, or shock; depression, suicidal ideation; decreased alertness, seizures, seizure disorder, unconscious state or coma, decreased alertness; pregnancy (category C); lactation.
Cautious Use
Cardiovascular, cerebrovascular, respiratory, renal, or hepatic disease; CNS depression, history of (chronic) depression or suicidal ideation; hypotension; vomiting; bradycardia; hypokalemia and hypomagnesemia; older adult; hypersensitivity to sulfite.
Route & Dosage
| "Off" Episodes of Parkinson's Disease Adult: SC Start with a test dose where BP can be closely monitored. Escalate test dose no sooner than 2 h after last dose until dose is not tolerated or patient has response. If test dose of 0.2 mL (2 mg) is tolerated and has positive response, continue with 0.2 mL (2 mg); if no response, use test dose of 0.4 mL (4 mg); if tolerated and has a positive response, continue with 0.3 mL (3 mg); if 0.4 mL test dose is not tolerated, try 0.3 mL (3 mg) test dose; if 0.3 mL is tolerated, continue with 0.2 mL (2 mg). May increase by 1 mg every few days, generally should not exceed 0.4 mL (4 mg) as an outpatient. Max dose: 0.6 mL as single injection and max 5 injections/d. If therapy is interrupted for 1 wk, restart with 2 mg dose. |
Administration
Subcutaneous- The dosing pen is marked in mL, not mg, increments; a 1 mg dose is equal to 0.1 mL.
- Aspirate to avoid intravascular injection and ensure the injection is SC and not intradermal.
- Rotate SC sites to reduce skin reactions.
- If the patient has not received apomorphine in more than 1 wk, reinstitute it by starting with the initial test dose and titrating to the desired dose.
- Apomorphine SC causes nausea and vomiting; thus the recommendation is to give 300 mg of trimethobenzamide PO t.i.d., starting 3 d before the first injection and continued for at least the first 2 mo of treatment.
- Store at 15°–30° C (59°–86° F).
Adverse Effects (≥1%)
Body as a Whole: Weakness, yawning, tiredness. CNS: CNS depression, dizziness, drowsiness, headache, lightheadedness, euphoria, restlessness, tremor, depression, dyskinesias , hallucinations. CV: Acute circulatory failure, bradycardia, hypertension, orthostatic hypotension, QT prolongation, vasovagal response, syncope. GI: Nausea , vomiting , hypersalivation, taste perversions. Metabolic: Peripheral edema. Respiratory: Respiratory depression, tachypnea, cough, pharyngitis, rhinitis. Skin: Contact dermatitis, bruising , granuloma, pruritus, sweating. Urogenital: Frequent penile erections, painful erections.Interactions
Drug: Alosetron, dolasetron, granisetron, ondansetron, palonosetron may cause severe hypotension and unconsciousness; alfuzosin, amoxapine, bepridil, chloroquine, clozapine, cyclobenzaprine, droperidol, flecainide, halofantrine, halothane, levomethadyl, local anesthetics, macrolides (clarithromycin, erythromycin, troleandomycin), maprotiline, mefloquine, methadone, pentamidine, phenothiazines, probucol, gatifloxacin, gemifloxacin, grepafloxacin, levofloxacin, moxifloxacin, sparfloxacin, tacrolimus, tricyclic antidepressants, amiodarone, clozapine, disopyramide, dofetilide, dolasetron, haloperidol, ibutilide, mesoridazine, palonosetron, pimozide, procainamide, quinidine, thioridazine, sotalol, ziprasidone may exacerbate QTc prolongation; may increase CNS depression with other CNS depressants, including tricyclic antidepressants, anxiolytics, sedatives, hypnotics, dronabinol, general anesthetics, mirtazapine, nefazodone, opiate agonists, pramipexole, ropinirole, skeletal muscle relaxants, tramadol, trazodone. Herbal: Kava may increase the symptoms of Parkinson's disease.Pharmacokinetics
Absorption: SC absorption dependent on site utilized—abdominal injection absorbed faster than thigh; lowering the temperature of the injection site slows absorption. Onset: 7–14 min. Peak: 40–60 min. Duration: Up to 2 h. Distribution: 85–90% protein bound. Metabolism: Metabolized by glucuronidation, sulfation, and N-demethylation. Elimination: Excreted by kidneys. Half-Life: 30–60 min.Nursing Implications
Assessment & Drug Effects
- Periodic ECG, especially in those with known CV disease.
- Withhold drug & notify physician for S&S of torsades de pointes (i.e., palpitations and syncope), especially in those with bradycardia or suspected hypokalemia or hypomagnesemia.
- Lab tests: Periodic serum electrolytes.
- Monitor closely for orthostatic hypotension, especially when doses are increased, and in patients taking antihypertensive medications and vasodilators (especially nitrates).
Patient & Family Education
- The dosing pen is marked in mL (not mg) increments; a 1 mg dose is equal to 0.1 mL.
- Avoid the use of alcohol while taking this drug.
- Report promptly any of the following: irregular or fast, pounding heartbeat, or palpitations; dizziness, lightheadedness, or fainting; unexplained weakness, tiredness, or sleepiness; confusion, hallucinations, or depression; unusual body movements; vomiting; or prolonged painful erections.
- Do not engage in potentially hazardous activities until reaction to drug is known.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug