Vareniclina

What is Varenicline?

Varenicline is a prescription medicine used to help adults stop smoking. It works by targeting nicotine receptors in the brain that are involved in addiction.

Smoking causes dependence because nicotine stimulates certain receptors in the brain that release dopamine, a chemical linked to pleasure and reward. Over time, the brain becomes dependent on nicotine to maintain these signals.

Varenicline helps break this cycle by partially activating these nicotine receptors. This reduces cravings and withdrawal symptoms while also decreasing the rewarding effects of cigarettes if you smoke during treatment.

Varenicline is typically used as part of a structured smoking cessation plan and works best when combined with behavioural support and motivation to quit.

What is it used for?

Varenicline is used to help adults quit smoking.

When you stop smoking, your body may experience withdrawal symptoms such as:

• Strong nicotine cravings
• Irritability
• Anxiety
• Difficulty concentrating
• Increased appetite
• Sleep disturbances

Varenicline helps reduce these symptoms by partially stimulating nicotine receptors in the brain.

It also blocks nicotine from cigarettes from fully activating these receptors. This means that if you smoke while taking varenicline, the cigarette will feel less satisfying.

By reducing cravings and the rewarding effects of nicotine, varenicline increases the chances of successfully quitting smoking.

How does the product work?

Varenicline works by interacting with nicotinic acetylcholine receptors in the brain.

These receptors normally respond to nicotine from cigarettes.

Varenicline acts as a partial agonist, meaning it both stimulates and blocks these receptors.

This produces two important effects:

1. Reduced cravings and withdrawal symptoms
Varenicline partially stimulates the receptors, helping maintain dopamine release at a lower level. This reduces withdrawal symptoms when you stop smoking.

2. Reduced reward from cigarettes
If you smoke while taking varenicline, the medication blocks nicotine from fully activating the receptors. This reduces the pleasurable effects of smoking.

Because of this dual action, varenicline can help you gradually break nicotine dependence.

Who should not use the product?

You should not use varenicline if:

• You are allergic to varenicline or any ingredient in the medicine
• You have experienced a serious allergic reaction to varenicline in the past

Varenicline should be used with caution if you:

• Have kidney disease
• Have a history of depression or other mental health conditions
• Have previously experienced behavioural changes while using smoking cessation medicines

Always inform your doctor about your full medical history before starting treatment.

Pregnancy and breastfeeding

If you are pregnant or planning pregnancy, speak to a doctor before using varenicline.

Although stopping smoking during pregnancy is strongly recommended, varenicline may not always be the preferred option. Your doctor will help determine the safest approach.

Varenicline may pass into breast milk. If you are breastfeeding, discuss the risks and benefits with your doctor before starting treatment.

How to use and dosage

Always take varenicline exactly as prescribed.

Treatment usually begins one week before your planned quit date.

The dose is gradually increased during the first week to help your body adjust:

• Days 1–3: low starting dose once daily
• Days 4–7: low dose twice daily
• From day 8 onwards: maintenance dose twice daily

The standard treatment course usually lasts 12 weeks. In some cases, treatment may be extended to help maintain smoking abstinence.

Take the tablets:

• After eating
• With a full glass of water

Do not stop taking varenicline without medical advice unless you experience significant side effects.

Possible side effects

Like all medicines, varenicline can cause side effects, although not everyone experiences them.

Common side effects include:

• Nausea
• Sleep disturbances
• Vivid dreams
• Headache
• Insomnia

Other possible side effects include:

• Dizziness
• Constipation
• Gas or indigestion
• Changes in appetite

Some people may experience mood changes or behavioural changes during treatment.

If you or people around you notice unusual changes in mood, behaviour or thinking, contact your doctor.

Important safety information

Before starting varenicline, tell your doctor if you:

• Have kidney disease
• Have a history of depression or anxiety
• Have previously experienced seizures
• Are taking other medicines that affect the nervous system

Varenicline may cause dizziness or sleepiness in some people. If this occurs, avoid driving or operating machinery.

Alcohol tolerance may change during treatment, so it is advisable to limit alcohol intake until you know how the medicine affects you.

Support programmes, counselling or behavioural therapy may further improve your chances of quitting smoking successfully.

When to seek medical help

Seek urgent medical attention if you experience:

• Severe allergic reaction (swelling of face, lips or throat)
• Difficulty breathing
• Chest pain
• Seizures

Contact your doctor if:

• You experience severe nausea or persistent vomiting
• You notice significant mood changes
• You develop depression, anxiety or unusual behaviour
• You experience persistent side effects

If you are unsure whether your symptoms are related to your medication or nicotine withdrawal, you can book a secure video consultation with a licensed doctor via Transtoyou for personalised advice. If symptoms are severe or sudden, seek urgent medical care immediately.