Drug Detail:Paxil (Paroxetine [ pa-rox-a-teen ])
Drug Class: Selective serotonin reuptake inhibitors
1. How it works
- Paxil is a brand (trade) name for paroxetine. Paroxetine is a medicine that may be used in the treatment of depression and other mood disorders.
- Experts believe paroxetine's effects are due to its ability to rebalance chemicals in the brain, such as serotonin, that are imbalanced in people with anxiety, depression, and other disorders.
- Its activity against other neurotransmitters is much less potent than other antidepressants.
- Paxil belongs to a group of medicines called Selective Serotonin Reuptake Inhibitors (SSRIs). SSRIs are thought to work by preventing the reuptake of serotonin by nerves, leading to an increase in serotonin concentrations within the nerve synapse (space between two nerves).
2. Upsides
- Used in the treatment of moderate-to-severe depression (Major Depressive Disorder).
- May reduce feelings of anxiety in people with obsessive-compulsive disorder (OCD), panic disorder, posttraumatic stress disorder (PTSD), or social or generalized anxiety disorder.
- Paxil is available as a generic under the name paroxetine.
3. Downsides
If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:
- Drowsiness, headache, nausea, agitation, sweating, dry mouth, gastrointestinal disturbances, tremor, loss of energy, decreased appetite or abnormal ejaculation are some of the more commonly reported side effects.
- As with other antidepressants, Paxil may increase the risk of suicidal thoughts or behavior particularly in young adults under the age of 24. Monitor for worsening mood.
- May impair your judgment and affect your ability to drive or operate machinery. Alcohol is best avoided.
- Interaction or overdosage may cause serotonin syndrome (symptoms include mental status changes [such as agitation, hallucinations, coma, delirium]), fast heart rate, dizziness, flushing, muscle tremor or rigidity and stomach symptoms (including nausea, vomiting, and diarrhea). Another serious syndrome called Neuroleptic Malignant Syndrome has also been reported; symptoms include high body temperature, muscle rigidity, and mental disturbances; discontinue immediately and seek urgent medical advice.
- May increase the risk of bleeding, especially if used with other drugs that also increase bleeding risk.
- May precipitate a manic episode in people with undiagnosed bipolar disorder.
- May cause lowering of total body sodium (called hyponatremia); elderly people or people taking diuretics or who are already dehydrated may be more at risk.
- May cause a discontinuation syndrome if abruptly stopped. Symptoms include irritability, low mood, dizziness, electric shock sensations, headache, and confusion.
- May not be suitable for some people including those susceptible to angle-closure glaucoma or taking certain medications such as thioridazine or pimozide.
- Infants exposed to Paxil during the first trimester of pregnancy have an increased risk of birth defects, particularly cardiovascular birth defects. If a woman becomes pregnant during treatment with Paxil she should be advised of the potential risks to the fetus and offered the choice of discontinuing treatment with Paxil, switching to another antidepressant, or continuing with Paxil if the benefits outweigh the risks. Only initiate Paxil in women who are already pregnant or intending to become pregnant if other treatment options are not suitable. Paxil is excreted into breastmilk and the infant should be monitored for adverse effects and breastfeeding discontinued if any are apparent.
- Rarely causes seizures.
Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects
4. Tips
- Swallow Paxil tablets whole, do not crush or chew. May be taken with or without food.
- Be alert for changes in behavior including agitation, depressed mood, and suicide-related events and seek medical advice if changes are apparent.
- Do not drive or operate machinery until the full effects of Paxil are known as it may impair your judgment and affect your ability to drive or operate machinery.
- Report any problems with bleeding or bruising to your doctor, also report any unexplained skin changes (such as blisters or rashes), problems with urination, eye pain or swelling and vision changes to your doctor.
- Children and adolescents should have their height and weight monitored during treatment.
- Do not stop suddenly as withdrawal symptoms may occur. Taper off slowly on a doctor's advice.
- Seek medical advice if a rash develops while taking Paxil. Discontinue if a severe allergic reaction to Paxil occurs.
- Do not take other medications with Paxil without first talking to your doctor or pharmacist as it may interact with some other drugs including St John's Wort and tramadol.
- Seek urgent medical advice if symptoms consistent with serotonin syndrome (such as agitation, hallucinations, fast heart rate, dizziness, flushing, nausea, diarrhea) or Neuroleptic Malignant Syndrome (symptoms include a high body temperature, muscle rigidity, or mental disturbances) develop.
- Tell your doctor if you are pregnant, intending to become pregnant, or are breastfeeding because Paxil may not be suitable for you.
5. Response and effectiveness
- Peak plasma concentrations are reached in approximately five hours. Some improvement in the symptoms of depression or anxiety may be noticed within a few weeks; however, it may take up to six to eight weeks for the full effects of Paxil to develop.
6. Interactions
Medicines that interact with Paxil may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with Paxil. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.
Common medications that may interact with Paxil include:
- anticoagulants (blood thinners), such as warfarin, or other drugs that have blood thinning effects such as aspirin or NSAIDs
- anticonvulsants, such as phenytoin, phenobarbital, or primidone
- antipsychotics (such as butyrophenones, phenothiazines, or thioxanthenes) and atypical antipsychotics (eg, olanzapine, quetiapine, ziprasidone)
- any medication that may cause drowsiness, such as benzodiazepines (eg, diazepam, lorazepam), first-generation antihistamines (such as doxylamine or promethazine), metoclopramide, or opioids (such as codeine, morphine)
- diuretics, such as furosemide
- HIV medications (fosamprenavir or ritonavir)
- medications that may affect the heartbeat, such as amiodarone, encainide, or flecainide
- pimozide and other drugs that are metabolized by the same enzymes such as astemizole, cimetidine, cisapride, cyclosporine, ketoconazole, terfenadine, or triazolam
- other antidepressants, such as tricyclic antidepressants (eg, amitriptyline), monoamine oxidase inhibitors (eg, isocarboxazid, phenelzine, and tranylcypromine), and SSRIs (eg, fluoxetine, sertraline)
- other medications that affect serotonin, such as amphetamines, fentanyl, lithium, tramadol, triptans (eg, almotriptan, eletriptan, or sumatriptan), or St. John's Wort
- thioridazine
- others, such as procyclidine or theophylline.
Avoid drinking alcohol or taking illegal or recreational drugs while taking Paxil.
Note that this list is not all-inclusive and includes only common medications that may interact with Paxil. You should refer to the prescribing information for Paxil for a complete list of interactions.