Varenicline Tablets

What is Varenicline?

Varenicline is a prescription medication containing the active substance varenicline, which belongs to a class of drugs known as smoking cessation aids. It is specifically designed to help adults stop smoking by targeting the underlying nicotine addiction.

Mechanism of Action

Varenicline works through a dual-action mechanism in the brain:

• Partial Agonist Activity: Varenicline binds to the same nicotinic receptors in the brain that nicotine typically targets, but it only partially activates them. This results in reduced nicotine cravings and withdrawal symptoms.
• Nicotine Blockade: When varenicline occupies these receptors, it prevents nicotine from binding to them. If you do smoke while taking varenicline, the nicotine has less effect, making cigarettes less satisfying.

Think of varenicline as a "key" that fits into the brain's nicotine "locks" (receptors) but only turns them partway. This provides enough stimulation to ease withdrawal symptoms but not enough to deliver the full rewarding effects of nicotine. At the same time, it blocks nicotine from fitting into these same locks, reducing the pleasure you'd normally get from smoking.

What is Varenicline Used For?

Varenicline is indicated for smoking cessation in adults. It is designed to help motivated smokers quit by addressing both the physical and psychological aspects of nicotine dependence.

Approved Patient Groups

Before Using Varenicline

Essential considerations before initiating treatment:

Medical History Assessment

• Psychiatric disorders (depression, anxiety, bipolar disorder, schizophrenia)
• Heart or blood vessel problems
• Kidney disease or kidney problems
• Seizures or epilepsy
• Allergies to any medications
• History of skin reactions to medications

Required Baseline Considerations

1. Assess motivation and readiness to quit smoking
2. Evaluate psychiatric history and current mental state
3. Review cardiovascular health status
4. Consider kidney function (may require dosage adjustment)
5. Discuss a target quit date typically set for the second week of treatment

Varenicline Contraindications

Absolute contraindications where Varenicline must not be used:

Absolute Contraindications

• Allergic to varenicline or any of the other ingredients
• Under 18 years of age
• End-stage renal disease requiring dialysis

Special Warnings

Special Population Considerations

Elderly Patients

• No dosage adjustment based on age alone
• Elderly patients more likely to have decreased renal function
• Monitor renal function before and during treatment

Renal Impairment

• Mild-moderate impairment: No dose adjustment
• Severe impairment: 0.5 mg once daily, may increase to 0.5 mg twice daily if tolerated
• End-stage renal disease: Not recommended

Hepatic Impairment

• No dosage adjustment necessary
• Varenicline undergoes minimal hepatic metabolism

Varenicline and Other Medicines

Significant interactions requiring monitoring:

Medications That May Require Dose Adjustment After Smoking Cessation

• Theophylline: Used for breathing problems - may require monitoring and potential dose reduction
• Warfarin: Blood thinner - may require more frequent INR monitoring and potential dose adjustment
• Insulin: Diabetes medication - may require adjustment due to changed insulin sensitivity
• Caffeine: Clearance may decrease after smoking cessation, potentially increasing effects

Specific Medication Interactions

Cimetidine: Patients with severe kidney disease should avoid taking cimetidine (used for gastric problems) concurrently with varenicline as this may increase blood levels of varenicline.

Pregnancy & Breastfeeding

Pregnancy

• Preferable to avoid use during pregnancy
• Risks to developing fetus not fully known
• Benefits of quitting smoking should be weighed against potential risks

Breastfeeding

• Unknown if varenicline passes into breast milk
• Effects on nursing infant unknown
• Discuss with doctor whether to discontinue nursing or medication

Driving & Machine Operation

• Varenicline may cause dizziness, sleepiness, and in rare cases, transient loss of consciousness
• These effects could impair ability to drive or operate machinery safely
• Do not drive, operate complex machinery, or engage in any potentially hazardous activities until you know how varenicline affects you

Warning Signs to Watch For

• Feelings of dizziness or lightheadedness
• Excessive sleepiness or fatigue
• Visual disturbances
• Difficulty focusing or concentrating

Varenicline Ingredients

Active Substance

• Varenicline (as tartrate)

Excipients

Sodium Content

• Less than 1 mmol sodium (23 mg) per tablet
• Essentially 'sodium-free'

How to Use Varenicline

Setting a Quit Date

1. Before starting treatment, set a target quit date
2. Typically during the second week of treatment (between day 8 and day 14)
3. You may choose your own target quit date within 5 weeks after starting treatment
4. Write this date on your pack as a reminder

Treatment Approach

• You are more likely to stop smoking if you are motivated and have support
• Your doctor and pharmacist can provide advice and resources
• Varenicline is most effective when used as part of a comprehensive smoking cessation program that includes behavioral support

Varenicline Dosage Guidelines

Standard Titration Schedule

Treatment Duration

• Standard course: 12 weeks
• If successful after 12 weeks, additional 12 weeks may be recommended
• Total possible treatment: 24 weeks

Dose Adjustment Criteria

• If experiencing intolerable side effects, doctor may reduce dose to 0.5 mg twice daily
• For patients with kidney problems, dosage adjustment may be necessary
• Do not exceed recommended dosage

Administration Instructions

Step-by-step administration guide:

Dosage Timing

1. Take varenicline tablets at approximately the same times each day
2. For twice-daily dosing, take one tablet in the morning and one in the evening
3. Approximately 12 hours apart
4. Establishing a routine (e.g., with breakfast and dinner) can help remember

Administration Process

1. Swallow the tablet whole with a full glass of water
2. Varenicline can be taken with or without food
3. If experiencing nausea, taking with food may help reduce this side effect
4. Continue taking varenicline for the full prescribed course

Missed Dose Management

General Principles

• Do NOT double doses
• Take missed dose as soon as remembered

Time-Based Guidance

Overdose Information

Symptoms

• Nausea
• Vomiting
• Dizziness
• Increased heart rate
• Disorientation

Management

1. Seek immediate medical attention
2. Go to the nearest hospital emergency department
3. Take the medication package or remaining tablets with you
4. No specific antidote available - treatment is supportive

Possible Side Effects

Very Common (more than 1 in 10 people)

• Inflammation of the nose and throat
• Abnormal dreams
• Difficulty sleeping
• Headache
• Nausea

Common (1 in 10 to 1 in 100 people)

• Chest infection, inflammation of the sinuses
• Increased weight, decreased appetite, increased appetite
• Sleepiness, dizziness, changes in taste
• Shortness of breath, cough
• Heartburn, vomiting, constipation, diarrhoea, bloating, abdominal pain, toothache, indigestion, flatulence, dry mouth
• Skin rash, itching
• Joint ache, muscle ache, back pain
• Chest pain, tiredness

Serious Side Effects

How to Store Varenicline

Storage Conditions

• Keep out of sight and reach of children
• Do not use after expiry date
• Store below 25°C
• For bottle packs: Use within 28 days of first opening

Disposal

• Do not throw away via wastewater or household waste
• Ask pharmacist how to dispose of unused medicines
• These measures help protect the environment

Pack Information

What Varenicline Tablets Look Like

• 0.5 mg tablets: White to off-white, oval, biconvex, film-coated tablets marked "0.5" on one side
• 1 mg tablets: Light blue, oval, biconvex, film-coated tablets marked "1" on one side

Available Pack Presentations

• Treatment initiation packs containing both 0.5 mg and 1 mg tablets
• Follow-on (maintenance) packs containing only 1 mg tablets
• Bottle packs with child-resistant closures containing 56 tablets

Not all pack sizes may be marketed. The specific pack available will depend on your prescription and pharmacy stock.

Where Can I Buy Varenicline Online in the UK