Abstract Breakthrough cancer pain is a significant problem for many patients with cancer because of the fast onset and often unpredictable nature of the pain episodes. The rapid onset opioids therefore have a central role to play in the management of breakthrough cancer pain. The rapid onset opioid fentanyl buccal tablet provides a fast analgesic effect and is easy to administer. However, titration of the medication is essential in order to optimize the management of pain. This is because individual patient characteristics, comorbidities, and other treatments may influence the absorption, pharmacokinetics, and pharmacodynamics of drugs. It is therefore important to individualize treatment by determining the effective dose for each patient, which is the dose that provides adequate analgesia and minimizes undesirable adverse effects. Data from clinical studies of fentanyl buccal tablet show that patients' effective doses ranged from 100 to 800 μg per episode, highlighting the need for the titration process. Following successful dose titration, treatment with fentanyl buccal tablet can achieve significant pain relief as early as 10 minutes after administration, resulting in a high level of patient satisfaction.