A Study To Assess The Effects Of A Single Dose Of GSK598809 In Modulating Nicotine Reward

Inclusion Criteria: * Healthy male smokers aged 18-65 with a desire to quit smoking. * Body weight greater than 50kg and BMI within range 19 - 29.9 kg/m2 * Healthy with no significant medical, psychiatric or laboratory evaluation abnormality. Exclusion Criteria: * Positive pre-study urine drug/breath alcohol screen: positive HIV 1/2, Hepatitis B or Hepatitis C test at screening. * History of alcohol/drug abuse or dependence (other than nicotine) within 12 months of the study. * History of psychiatric disorder or sensitivity to any of the study medications or components thereof or a history of drug or allergy that in the opinion of the physician responsible contraindicates their participation. * History of cardiac or pulmonary disease/abnormalities.