Marinol
dronabinol
Pharmacologic class: Cannabinoid
Therapeutic class: Antiemetic
Controlled substance III
Pregnancy risk category B
Action
Unknown. May exert antiemetic effect by inhibiting vomiting control mechanism in medulla oblongata.
Availability
Capsules: 2.5 mg, 5 mg, 10 mg
Indications and dosages
➣ Prevention of nausea and vomiting caused by chemotherapy
Adults and children: Initially, 5 mg/m2 P.O. 1 to 3 hours before chemotherapy. Repeat dose q 2 to 4 hours after chemotherapy, up to four to six doses per day. If 5-mg/m2 dose is ineffective and patient has no significant adverse reactions, dosage may be increased in increments of 2.5 mg/m2 to a maximum dosage of 15 mg/m2.
➣ Appetite stimulant
Adults and children: Initially, 2.5 mg P.O. b.i.d. May reduce dosage to 2.5 mg/day given as a single evening or bedtime dose. Maximum dosage is 10 mg P.O. b.i.d.
Contraindications
• Hypersensitivity to cannabinoids or sesame oil
• Breastfeeding
Precautions
Use cautiously in:
• hypertension, heart disease, bipolar disorder, schizophrenia, drug abuse, seizures
• pregnant patients.
Administration
• When used to stimulate appetite, give before lunch and dinner.
Adverse reactions
CNS: drowsiness, anxiety, impaired coordination, irritability, depression, headache, hallucinations, memory loss, paresthesia, ataxia, paranoia, disorientation, nightmares, speech difficulties, syncope, suicidal ideation
CV: tachycardia, hypotension, hypertension
EENT: visual disturbances, tinnitus
GI: dry mouth
Skin: facial flushing, diaphoresis
Interactions
Drug-drug. Anticholinergics, antihistamines, tricyclic antidepressants: increased tachycardia and hypertension
CNS depressants: increased CNS depression
Ritonavir: increased dronabinol blood level and risk of toxicity
Drug-behaviors. Alcohol use: increased CNS depression
Patient monitoring
• Monitor vital signs for hypotension and tachycardia.
See Check for adverse CNS reactions. Report significant depression, paranoid reaction, or emotional lability.
• Monitor nutritional status and hydration.
Patient teaching
• Teach patient about drug's significant adverse CNS and cardiovascular effects. Emphasize that he should take it only as prescribed and needed.
See Advise patient (and significant other) to immediately report depression, suicidal thoughts, paranoid reactions, seizures, and other serious CNS reactions.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and behaviors mentioned above.
dronabinol
(droe-nab-i-nol) dronabinol,delta-9-tetrahydrocannabinol
(trade name),THC
(trade name),Marinol
(trade name)Classification
Therapeutic: antiemeticsPharmacologic: cannabinoids
Indications
Action
Therapeutic effects
Pharmacokinetics
Time/action profile (antiemetic effect)
| ROUTE | ONSET | PEAK | DURATION |
| PO | unknown | 2–4 hr | 4–6 hr† |
Contraindications/Precautions
Adverse Reactions/Side Effects
Central nervous system
- anxiety (most frequent)
- concentration difficulty (most frequent)
- confusion (most frequent)
- dizziness (most frequent)
- drowsiness (most frequent)
- mood change (most frequent)
- abnormal thinking
- depression
- disorientation
- hallucinations
- headache
- impaired judgment
- memory lapse
- paranoia
Ear, Eye, Nose, Throat
- dry mouth (most frequent)
Cardiovascular
- palpitations
- syncope
- tachycardia
Gastrointestinal
- abdominal pain
- nausea
- vomiting
Dermatologic
- facial flushing
Neurologic
- ataxia
- paresthesia
Miscellaneous
- physical dependence
- psychological dependence (high doses or prolonged therapy)
Interactions
Drug-Drug interaction
Additive CNS depression with alcohol, antihistamines,barbiturates, benzodiazepines, atropine, scopolamine,lithium, buspirone, muscle relaxants, opioid analgesics, tricyclicantidepressants, and sedative/hypnotics.Increased risk of tachycardia with amphetamine, atropine, scopolamine, cocaine, sympathomimetics, antihistamines, and tricyclicantidepressants.May increase blood levels of theophylline.Increased risk of tachycardia with caffeine -containing herbs (cola nut, guarana, mate, tea, coffee).Concomitant use of kava, valerian, skullcap, chamomile, or hopscan increase CNS depression.Route/Dosage
Availability (generic available)
Nursing implications
Nursing assessment
- Assess nausea, vomiting, appetite, bowel sounds, and abdominal pain prior to and following the administration of this drug.
- Monitor hydration, nutritional status, and intake and output. Patients with severe nausea and vomiting may require IV fluids in addition to antiemetics.
- Monitor BP and heart rate periodically throughout therapy.
- Patients on dronabinol therapy should be monitored closely for side effects because the effects of dronabinol vary with each patient.
Potential Nursing Diagnoses
Risk for deficient fluid volume (Indications)Imbalanced nutrition: less than body requirements (Indications)
Risk for injury (Side Effects)
Implementation
- Dronabinol capsules should be refrigerated (not frozen).
- Physical or psychological dependence may occur with high doses or prolonged therapy, causing a withdrawal syndrome (irritability, restlessness, insomnia, hot flashes, sweating, rhinorrhea, loose stools, hiccups, anorexia) when discontinued. This is unlikely to occur with therapeutic doses and short-term use of dronabinol.
- Antiemetic: This drug may be administered prophylactically 1–3 hr prior to chemotherapy and repeated every 2–4 hr after chemotherapy up to 4–6 doses daily. Most patients respond to 5 mg three or four times daily.
- Appetite Stimulant: Give 2.5 mg twice daily before lunch and supper initially. Reduce dose to 2.5 mg/day in the evening or at bedtime for patients unable to tolerate 5 mg/day dose. May increase dose to 2.5 mg at lunch and 5 mg before supper or 5 mg at lunch and 5 mg after supper if further therapeutic effect is desired and adverse effects are minimal. Most patients respond to 2.5 mg twice daily dose, but up to 10 mg bid have been tolerated in about 50% of patients. Adverse effects are dose related.
Patient/Family Teaching
- Instruct patient to take dronabinol exactly as directed. Take missed doses as soon as possible but not if almost time for next dose; do not double doses. Signs of overdose (mood changes, confusion, hallucinations, depression, nervousness, fast or pounding heartbeat) may occur with increased doses.
- Advise patient to call for assistance when ambulating, because this drug may cause dizziness, drowsiness, and impaired judgment and coordination. Avoid driving or other activities requiring alertness until response to the drug is known.
- Instruct patient to change positions slowly to minimize orthostatic hypotension.
- Caution patient to avoid taking alcohol or other CNS depressants during dronabinol therapy.
- Advise patient and family to use general measures to decrease nausea (begin with sips of liquids and small, nongreasy meals; provide oral hygiene; remove noxious stimuli from environment).
Evaluation/Desired Outcomes
- Prevention of and decrease in nausea and vomiting associated with chemotherapy.
- Increased or maintained weight in patients with AIDS.