Paroxetine HCL (Paxil)

What is Paroxetine?

Paroxetine is an SSRI (selective serotonin reuptake inhibitor). SSRIs are a class of medications commonly prescribed as antidepressants, but were also found to be effective in reducing hot flashes in menopausal women. 

How Paroxetine works

Paroxetine is a selective serotonin reuptake inhibitor (SSRI). Serotonin is a chemical in your brain that is involved in nerve signaling and is often considered to be the ‘happiness hormone’. Serotonin also plays a role in helping you maintain a stable body temperature. Paroxetine works by reducing the amount of serotonin that can be reabsorbed by your cells, meaning there is more serotonin available. If more serotonin is available, you should be able to better regulate your body temperature.

What is Paroxetine used for?

Paroxetine can be used to treat hot flashes, but it is also used to treat several mental health conditions, including:

• Depression
• Post-traumatic stress disorder (PTSD)
• Generalized anxiety disorder (GAD)
• Social anxiety disorder
• Obsessive-compulsive disorder (OCD)
• Panic disorder

How long does Paroxetine take to have an effect on hot flashes?

It can take a few weeks for Paroxetine to work. You should see a 33-67% reduction in the frequency of your hot flashes within 6-12 weeks. Some effects, including side effects, may occur shortly after you start taking Paroxetine.

How does Paroxetine make you feel?

Paroxetine usually takes about 4-6 weeks before having the intended effect. During this period, you may experience some side effects including anxiety or depression, but this varies from person to person. It is common to feel anxious or depressed initially when taking any SSRI medication but this should go away after the body becomes accustomed to the medication.  After 4-6 weeks, you should feel more like your usual self, and you should notice a reduction in your hot flashes. If you do not experience an improvement of symptoms at this time, or if you continue to experience significant side effects, you may want to speak to your doctor about alternatives. 

Active ingredient

The active ingredient in Paroxetine depends upon which type you take. Paroxetine is available with paroxetine mesylate or paroxetine hydrochloride as the active ingredient. 

Inactive ingredients

Inactive ingredients can vary across different manufacturers. Paxil is a branded version of Paroxetine manufactured by GlaxoSmithKline (GSK). It contains the following inactive ingredients: dibasic calcium phosphate dihydrate, hypromellose, magnesium stearate, polyethylene glycols, polysorbate 80, sodium starch glycolate, titanium dioxide and colorings.

Which Paroxetine ingredients can cause an allergic reaction?

Unless you are specifically allergic to one of the active or inactive ingredients, there is no ingredient normally associated with allergies. If you start taking Paroxetine and notice difficulty breathing, a rash or swelling of the tongue, face, eyes, or mouth, stop taking it immediately and proceed to the nearest emergency department. 

What is the Paroxetine dosage for hot flashes?

The Paroxetine dosage for hot flash treatment depends upon which type of Paroxetine you are taking:

• Paroxetine mesylate - 1 x 7.5mg tablet daily 
• Paroxetine hydrochloride - 1 x 10mg tablet daily or 1 x 20mg tablet daily
• Paroxetine hydrochloride (controlled release) - 1 x 12.5mg tablet daily or 1 x 25mg tablet daily

When should Paroxetine be taken?

Paroxetine should be taken once daily in the morning. Paroxetine should be taken with food to avoid side effects such as nausea. It is recommended that you take Paroxetine in the morning because it can cause difficulty sleeping. If you find it difficult to tolerate the side effects of Paroxetine during the day, you could try taking it at night instead. 

Can Paroxetine be crushed or cut in half?

Paroxetine is available in different forms. Regular Paroxetine and sustained release (or controlled release) tablets should not be crushed or cut in half, as this would cause the medication to be released too quickly, exacerbating potential side effects. 

Paroxetine side effects

Common side effects of Paroxetine include:

• Anxiety
• Impaired concentration
• Memory loss
• Drowsiness
• Confusion
• Dizziness
• Headache
• Tremor
• Altered taste
• Changes in appetite
• Weight changes
• Muscle weakness/muscle pain
• Joint pain
• Fever
• Constipation
• Diarrhea
• Nausea
• Vomiting
• Visual changes
• Tinnitus
• Difficulty sleeping
• Yawning

Please see the patient information leaflet for a full list of side effects. 

Contraindications

Paroxetine should not be taken by individuals with a seizure disorder. Individuals with bipolar disorder, clinical depression or a significant anxiety disorder should be evaluated in person before starting paroxetine.

Drug interactions

Over 450 drugs are known to interact with Paroxetine. This includes common drugs such as Zoloft and Aspirin, as well as some more unusual medications. Therefore, it is vital that you tell your doctor about any medications or recreational drugs that you are taking, to avoid any negative interactions. 

Can I drink alcohol when taking Paroxetine?

Alcohol can exacerbate the side effects of Paroxetine, such as dizziness, nausea, and confusion. Therefore, it is recommended that you avoid drinking alcohol while taking Paroxetine. 

Can I take Paroxetine when pregnant?

Paroxetine is not recommended during pregnancy, as it can increase the risk of birth defects if taken during the first trimester. The risk of birth defects has been found to increase by 23%, meaning that the overall risk of birth defects is 3.69% for women taking Paroxetine in their first trimester. Paroxetine would not be prescribed for hot flashes in pregnant women; as a hot flash treatment, Paroxetine would only be prescribed to menopausal women. 

Can I take Paroxetine when breastfeeding?

A small amount of Paroxetine can be passed into breast milk, and a small number of babies have experienced side effects from Paroxetine. However, this is not considered to be a significant risk, so breastfeeding mothers of healthy children may be able to take Paroxetine. The prescribing doctor will help you weigh up the risks and benefits of treatment before prescribing Paroxetine. Paroxetine would not be prescribed for hot flashes in breastfeeding women; as a hot flash treatment, Paroxetine is only given to menopausal women, however Paroxetine does have other uses such as the treatment of depression. 

Can Paroxetine make you sleepy?

Paroxetine can cause drowsiness and difficulty concentrating.  Some people however,  experience insomnia and difficulty sleeping when taking Paroxetine. 

Can Paroxetine cause headaches?

Headaches are a common side effect of Paroxetine. If you do experience headaches, you should avoid taking Aspirin as this can interact with Paroxetine. 

Can Paroxetine cause high blood pressure or low blood pressure?

When combined with some specific antidepressants, Paroxetine can cause very high blood pressure which can persist for a few weeks, even if you stop taking it.  Paroxetine will not lower blood pressure. Other antidepressants that can increase blood pressure are: Venlafaxine (Effexor XR), Monoamine oxidase inhibitors, Tricyclic antidepressants and Fluoxetine (Prozac, Sarafem, others)

Paroxetine vs HRT

Hormone replacement therapy is usually suggested for menopausal women experiencing hot flashes. Some women prefer to avoid hormone-based treatment, and in this case, antidepressants such as Paroxetine or Venlafaxine may be prescribed. Additionally, paroxetine may be better suited for women who have been diagnosed with breast cancer, specifically those who are not taking Tamoxifen. 

Antidepressants for hot flashes

Antidepressants such as Paroxetine and Venlafaxine are effective medications for hot flashes in menopausal women. However, not all antidepressants are considered to be effective in treating hot flashes. For example, Sertraline and Fluoxetine do not have any proven effect in this regard.

Paroxetine or Venlafaxine

Paroxetine and Venlafaxine are equally effective in the treatment of hot flashes, however, only Paroxetine has FDA approval for this indication.  Paroxetine is therefore, often the first-choice for treatment when HRT is considered unsuitable. When Venlafaxine is prescribed for hot flashes, it is considered off-label use.