Clonidine, an
alpha-2 agonist induces dose dependent anti-nociception mainly through stimulation of alpha-2 adrenoceptors in dorsal horn mimicking activation of descending inhibitory pathways.
At present, clonidine and dexmedetomidine are the two
alpha-2 agonist commonly used in clinical practice.
Non availability of u-receptor opioids forces the anesthetists working in some parts of the world to use substitutes like nalbuphine; which is a k-receptor agonist and antagonist at u-opioid1; or tramadol, which acts as a weak u agonist with additional
alpha-2 agonist activity and weak inhibitor of norepinephrine and serotonin reuptake2.
Xylazine, an dose
alpha-2 agonist, produces a dose-related degree of sedation and its intravenous injection results in deeper sedation than intramuscular administration (Clarke et al.
3,4) If concerned, however, alternative ADHD treatment such as
alpha-2 agonist treatment could be considered.
In spite of its popularity in the western countries as an alternative therapy for the menopausal vasomotor problems, centrally active
alpha-2 agonist clonidine is only marginally more effective than placebo, but considerably less efficient than estrogen [5].
Injectable drug company Hospira Inc (NYSE:HSP) revealed on Monday that the US Food and Drug Administration (FDA) has awarded pediatric exclusivity for its
alpha-2 agonist Precedex (dexmedetomidine HCl) injection.
Antinociceptive response to an exogenous
alpha-2 agonist is mediated by an alpha-2A adrenoceptor (20).
23) The combination of an
alpha-2 agonist and local anesthetic agent was also shown to produce longer-lasting analgesia.
The
alpha-2 agonist clonidine (6) may be used to relieve adrenergic withdrawal symptoms.
However, due to severe side effects like muscle rigidity, frequent convulsions, and rough recoveries, these agents should only be used in combination with an
alpha-2 agonist or another tranquilizing or sedative drug (Kreeger et al.
