Marijuana and Prescription Drugs
Weed can prompt adverse drug interactions with many specific prescription medications and even entire drug classes. Either may intensify the effects of the other, or marijuana may interfere with a medication’s desired effects.
Some specific medications should never be taken with marijuana because of adverse effects include:
- Antipyrine (NSAID for inflammation and fever) – Marijuana slows down how quickly the body metabolizes antipyrine, leading to increased side effects.
- Cartizem/Diltiazem (treats angina, arrhythmia, and hypertension) – Marijuana use impairs absorption and increases side effects.
- Chlorzoxazone (muscle relaxant for spasms) –Marijuana may reduce this medication’s effectiveness.
- Ciclosporin (immunosuppressive given for rheumatoid arthritis, Crohn’s disease, psoriasis, and organ reception) – Marijuana increases the speed of metabolization, increasing possible side effects.
- Clarithromycin/Biaxin (given to treat bacterial infections) – Because marijuana slows down how the liver breaks down this medication, side effects are intensified.
- Disulfiram/Antabuse (anti-drinking medication)—Using cannabis with disulfiram may induce hypomania—excitability, disinhibition, and irritability.
- Estrogen (birth control and menopause) – Marijuana slows down absorption, leading to worsened side effects.
- Indinavir/Crixivan (HIV/AIDS treatment) – Marijuana decreases the speed with which this drug is absorbed, causing increased side effects.
- Isoflurane (general anesthetic) – Marijuana changes how isoflurane is broken down by the liver, decreasing its effectiveness.
- Lovastatin/Mevacor (anti-cholesterol) – Marijuana slows down absorption, increasing Lovastatin’s side-effects.
- Theophylline (treatment for COPD and asthma) – This medication is less effective when used simultaneously with marijuana.
Marijuana can also interfere with a patient taking their prescription medications as directed. Almost 8% of patients testing positive for cannabis also tested negative for their legitimately-prescribed medications.
Marijuana and Anticoagulants
Blood clotting is slowed by marijuana use, thereby increasing the risk of excessive bleeding and bruising. Some anticoagulants that should NEVER be taken in combination with weed include:
- Clopidogrel/Plavix (heart disease and stroke)
- Dalteparin/Fragmin (pulmonary embolism and thrombosis)
- Enoxaparin/Lovenox (pulmonary embolism and thrombosis)
- Heparin (pulmonary embolism, thrombosis, and arterial thromboembolism)
- Wafarin/Coumadin (pulmonary embolism, thrombosis, stroke prevention)
Marijuana and Antidepressants
Mixing antidepressants and marijuana can increase the side effects of the medication – confusion, difficulty concentrating, drowsiness, dizziness, cognitive impairment, poor judgment, and worsened motor coordination.
In addition, using weed while taking SSRI antidepressants may result in increased incidence of mania – racing thoughts, restlessness, distractibility, poor impulse control, and irritability.
Concurrent use of SNRI antidepressants and cannabis can cause the body’s serotonin levels to fluctuate wildly, possibly resulting in sudden serotonin syndrome, a potentially life-threatening condition characterized by poor coordination, jerky movements, tremors, and muscle rigidity.
Finally, both pot and tricyclic antidepressants can cause hypertension and tachycardia, even in individuals without a current heart condition.
Examples of SSRI antidepressants:
- Citalopram (Celexa)
- Escitalopram (Lexapro, Cipralex)
- Paroxetine (Paxil, Seroxat)
- Fluoxetine (Prozac)
- Fluvoxamine (Luvox, Faverin)
- Sertraline (Zoloft, Lustral)
Examples of SNRI antidepressants:
- Desvenlafaxine (Pristiq)
- Duloxetine (Cymbalta)
- Levomilnacipran (Fetzima)
- Milnacipran (Ixel, Savella)
- Venlafaxine (Effexor)
Examples of tricyclic antidepressants:
- Amitriptyline (Elavil, Endep)
- Amitriptylinoxide (Amioxid, Ambivalon, Equilibrin)
- Clomipramine (Anafranil)
- Desipramine (Norpramin, Pertofrane)
- Dibenzepin (Noveril, Victoril)
- Dimetacrine (Istonil)
- Dosulepin (Prothiaden)
- Doxepin (Adapin, Sinequan)
- Imipramine (Tofranil)
- Lofepramine (Lomont, Gamanil)
- Melitracen (Dixeran, Melixeran, Trausabun)
- Nitroxazepine (Sintamil)
- Nortriptyline (Pamelor, Aventyl)
- Noxiptiline (Agedal, Elronon, Nogedal)
- Opipramol (Insidon)
- Pipofezine (Azafen/Azaphen)
- Protriptyline (Vivactil)
- Trimipramine (Surmontil)
Marijuana and Antipsychotics
Antipsychotic medications are used to manage the symptoms of psychosis, especially as they present in patients with bipolar disorder or schizophrenia. However, using marijuana while taking an antipsychotic can result in reduced blood plasma levels of the medication. Not only does this limit their effectiveness, but cannabis use is also itself associated with psychotic events, worsened depressive episodes, and rapid, unpredictable mood cycling.
Complicating this problem is the fact that regular weed users are not typically compliant with their medication schedules. This is particularly important because missing even a single dose of a mood-stabilizing medication can trigger psychotic flareups.
Examples of FDA-approved antipsychotics include:
- Aripiprazole (Abilify)
- Asenapine Maleate (Saphris)
- Chlorpromazine (Thorazine)
- Clozapine (Clozaril)
- Droperidol (Innovar)
- Fluphenazine (Prolixin)
- Haloperidol (Haldol)
- Iloperidone (Fanapt)
- Lurasidone (Latuda)
- Molindobe (Moban)
- Olanzapine (Zyprexa)
- Paliperidone (Invega)
- Perphenazine (Trilafon)
- Pimozide (Orap)
- Quetiapine (Seroquel)
- Risperidone (Risperdal)
- Tiotixene (Navane)
- Ziprasidone (Geodon)
Marijuana and Barbiturates
Although they have largely been replaced as sleeping aids or anxiety medications by safer benzodiazepines, sedating barbiturates ARE still used. They are used to treat anxiety, insomnia, and cluster or migraine headaches. They are also used as general anesthetics and in assisted suicides. Drug experts caution against the simultaneous use of barbiturates and cannabis, because the combination may cause excessive drowsiness that can lead to accidents and injury.
Barbiturate medications include:
- Amobabital sodium
- Amytral sodium
- Butisol sodium
- Thiopental sodium
Marijuana and Benzodiazepines
Benzodiazepines are prescribed as anti-anxiety medications, sleeping aids, anticonvulsants, and muscle relaxants. As with barbiturates, the concurrent use of both benzos and weed can lead to over-sedation, with such side effects as confusion, inability to concentrate, excessive drowsiness. This can lead to accidents, injury, and dangerous dosage errors.
In the United States, the following benzodiazepines are approved by the FDA:
- Alprazolam/Xanax (anxiety and panic disorders)
- Chlordiazepoxide/Librium (anxiety and alcohol withdrawal)
- Clobazam/Onfi (anxiety and epileptic seizures)
- Clonazepam/Klonopin (panic disorder, seizures, and movement disorders)
- Clorazepate/Tranxene (anxiety, alcohol withdrawal, insomnia, and epileptic seizures)
- Diazepam/Valium (anxiety, alcohol/benzodiazepine/opioid dependence, insomnia, and panic attacks)
- Estazolam/ProSom (insomnia)
- Flunitrazepam/Rohypnol – “Roofies” are illegal in the United States but are used illicitly, primarily as a date rape drug.
- Flunitrazepam/Dalmane (mild/moderate insomnia)
- Lorazepam/Ativan (anxiety, alcohol withdrawal, insomnia, epileptic seizures, surgical procedure amnesia, and nausea or vomiting caused by chemotherapy)
- Midazolam/Versed (anxiety, anesthesia, insomnia, and sedation for medical procedures)
- Nitrazepam/Alodorm (insomnia and age-dependent epilepsy)
- Oxazepam/Seresta (insomnia, anxiety, alcohol withdrawal) – Oxazepam is the most-frequently detected illicitly-used prescription drug among recreational marijuana users.
- Quazepam/Doral (insomnia)
- Temazepam/Restoril (severe insomnia)
- Triazolam/Halcion (anxiety for medical or dental procedures, jet lag)
Although they are considered safe and effective for short-term use, benzodiazepines are among the most addictive and abused prescription medications. The use of any mood-altering substance – in this case, marijuana – that helps prime the brain for addiction is discouraged.