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 .
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.