Tramadol Hydrochloride Pharmacokinetics Absorption Bioavailability. Rapidly and almost completely absorbed following oral administration; mean absolute bioavailability of conventional tablets is approximately 75%. 1 51 Bioavailability of 200-mg extended-release tablet is 85–90% of that of conventional tablets given at equivalent daily dosage. Tramadol is used primarily to treat mild to severe pain, both acute and chronic. Its analgesic effects take about one hour to come into effect and 2 to 4 h to peak after oral administration with an immediate-release formulation. Tramadol may only be used with particular caution in opioid-dependent patients, patients with head injury, shock, a reduced level of consciousness of uncertain origin, disorders of the respiratory centre or function, increased intracranial pressure. HIGHLIGHTS OF PRESCRIBING INFORMATION These highlights do not include all the information needed to use tramadol hydrochloride extended-release capsules safely and effectively. Tramadol Tablets official prescribing information for healthcare professionals. Includes: indications, dosage, adverse reactions, pharmacology and more. If you have any side effects from tramadol, let your doctor know right away. The most common side effects are dizziness, nausea, constipation, and headache. DRUG ABUSE AND DEPENDENCE. Abuse Tramadol has mu-opioid agonist activity.Tramadol hydrochloride can be abused and may be subject to criminal diversion. Tolerance, psychic and physical dependence may develop, especially after long-term use. When a patient no longer requires therapy with tramadol, it may be advisable to taper the dose gradually to prevent symptoms of withdrawal. Learn about Ultram (Tramadol Hcl) may treat, uses, dosage, side effects, drug interactions, warnings, patient labeling, reviews, and related medications. Learn about Ultracet (Tramadol Hydrochloride and Acetaminophen Tablets) may treat, uses, dosage, side effects, drug interactions, warnings, patient labeling, reviews, and related medications.