Cimetidine-  coadministration of cimetidine and varenicline  increased the systemic exposure of
varenicline because of reduction in renal clearance of varenicline

Smoking cessation

CNS-         headache  18%    abnormal dreams 8%    lethargy, nightmare, sleep disorder 2%

GI -          abdominal pain 4%   dyspepsia 4%    flatulence 8%    nausea  15%

Metabolic -   increased appetite 3%

Respiratory -    dyspnea  2%     upper respiratory disorder  6%

Special senses-     dysgeusia    7%

Miscellaneous-      fatigue/malaise  3%

Pregnancy-  use only if benefits outweighs the potential risk

Lactation- decide whether to discontinue breast feeding or the drug depending on the importance of
drug to the mother.

Children- safety and efficacy for use in children  is not established

New Drugs Approved by (DCI) Drug Controller  GENERAL -  India  For Marketing                                                                                            (Ref- IDMA Publication)

Indication-
Smoking cessation

Dosage-
Varenicline should be taken after eating and with a full glass of water.

Usual dosage - 1mg twice daily following 1-week titration as follows-

Days  1 through to 3                           0.5mg once daily
           4 through to 7                          0.5mg twice daily
           8 through end of treatment     1mg twice daily 

Duration of treatment-

Patients should be treated with varenicline for 12 weeks.
For patients who have successfully stopped smoking at the end of 12 weeks,
an additional course of 12 weeks of treatment is recommended with varenicline
to further increase the likelihood of long-term abstinence,

1. Instruct patient to set up a quit date of smoking and initiate varenicline 1 week before
   the quit date

2. Advice patients to take varenicline after eating and with a full glass of water.

3. Instruct patient how to titrate varenicline  beginning with a dose of 0.5mg for the first 3    days   for the next four days 0.5mg one in the morning and one in the evening

4. Advice patients that after the first 7 days, the dose should be increased one 1mg tablet  in  the  morning and 1 in the evening

5. Advice patients to continue to attempt to quit if they have early lapses after the quit date.
 
6. Inform patients that insomnia are side effects of varenicline and are usually trancient

7. Provide patients with educational materials and necesary counselling to support an
    attempt to quit smoking

8. Inform patients that some medications may require dose adjustments after quitting smoking

9. Advice patients intending to become pregnant or breast feeding an infant of the risks      of  smoking and the risks and benefits of smoking cessation with varenicline

Pregnancy- 
Use only if benefits outweighs the potential risk

Lactation-
Decide whether to discontinue breast feeding or the drug depending on the importance of
drug to the mother.

Children-
Safety and efficacy of use in children  is not established