Drugs cholinergic

GioHnergic drugs mimic die activity of tiie iiarasymiia-tiietic nervous system (PNS). They also are called parasympathomimetic drugs. An understanding of tiie PNS is useful in understanding tiie cliohnergic dni.  

The PNS is a part of tiie autonomic nervous system (see (])liap. 22). It helps conserve body energy and is partly responsible for activities such as slowing tiie heart rate, digesting food, and eliminating body wastes. 

Electron microscopic study reveals an incalculably small sjiace between nerve ending and tiie effector oigan (eg, tiie muscle, cell, or biid) tiiat is innervated (or controlled) by a nerve fiber. Fbr a nerve impulse to be transmitted from tiie nerve ending (motor end plate) across tiie sjiace to tiie effector oigan, a neurohormone is needed. 

The PNS has two neurohormon (neurotransmitters) acetylcholine (ACh) and acetylcholinesterase (AC3iE). AC3i is a neurotransmitter responsible for tiie transmission of nerve impulses to effector cells of tiie parasympatiietic nervous system. A(3i plays an important role in tiie transmission of nerve impulses at synaiDses and myoneural junctions. AQi is quickly 

Cholinergic dru have limited usefulness in medicine, partly because of the adverse reactions that may occur during administration. However, in some diseases or conditions cholineigic dru are eitiier definitely indicated or may be of valua 

---

Discuss the uses, drug actions, general adverse reactions, contraindications, precautions, and interactions of the cholinergic drugs. 

Identify important preadministration and ongoing assessment activities the nurse should perform on the patient taking cholinergic drugs. 

Discuss ways to promote an optimal response to therapy, how to manage common adverse reactions, and important points to keep in mind when educating the patient about the use of cholinergic drugs. 

URINARY RETENTION. If a patient receives a cholinergic drug for the treatment of urinary retention, die nurse palpates die abdomen in the pelvis area to determine if distention is present. A rounded swelling over die pelvis usually indicates retention and a distended bladder. The patient may also complain of discomfort in the lower abdomen. In addition, die nurse takes die patient s blood pressure and pulse rate... 

While die patient is receiving a cholinergic drug it is important for the nurse to monitor for drug toxicity or cholinergic crisis. 

GLAUCOMA When a cholinergic drug is used to treat glaucoma, die nurse checks the eye and die area around die eye daily for evidence of redness, inflammation, and excessive secretions, particularly if die ocular system is used. If secretions are present around die eye, the nurse removes them with a cotton ball or gauze soaked in normal saline or other cleansing solution recommended by die primary health care provider. 

If a cholinergic drug is ordered for the prevention of urinary retention, die nurse measures and records the fluid intake and output. If die amount of each voidingis insufficient or die patient fails to void, the nurse palpates the bladder to determine its size and notifies the primary healdi care provider. 

The expected outcomes of the patient depend on die reason for administration of the cholinergic drug but may include an optimal response to dierapy, management of common adverse drug effects, and an understanding of and compliance with the prescribed tiierapeutic regimen. 

The care of a patient receiving a cholinergic drug depends on the drug used, the reason for administration, and the patient s response to the drug. 

GLAUCOMA When a cholinergic drug is prescribed for glaucoma, the nurse instructs tlie patient and a family member in instillation of the eye drops (see Fhtient and Family Teaching Checklist Instilling Liquid Eye Medications). 

Discuss the types of ongoing assessments made when a patient takes a cholinergic drug for urinary retention. 

Damsma, G., Westernik, B.H., de Vries, J.B., and Horn, A.S., The effect of systemically applied cholinergic drugs on the striatal release of dopamine and its metabolites, as determined by automated microdialysis in conscious rats, Neurosci. Lett., 89, 349, 1988. 

Segerberg, M.A. and Stretton, A.O. (1993) Actions of cholinergic drugs in the nematode Ascaris mum. Complex pharmacology of muscle and motomeurons. Journal of General Physiology 101,271—296. 

Batra S (1990) Interaction of antiestrogens with binding sites for muscarinic cholinergic drugs and calcium channel blockers in cell membranes. Cancer Chemother Pharmacol 26 310-312... 

The symptoms that followed the daily intramuscular administration of D.F.P. for 5 days mimicked most of the muscarine-like and nicotine-like effects (see p. 37) of cholinergic drugs. There were also effects on the central nervous system. 

McPhillips JJ. 1969b. Subsensitivity of the rat ileum to cholinergic drugs. J Pharmacol Exp Ther 166 249-254. 

Hironaka N, Ando K. (1996). Effects of cholinergic drugs on scopolamine-induced memory impairment in rhesus monkeys. Nihon Shinkei Seishin Yakurigaku Zasshi. 16(3) 103-8. 

Lilienfeld, S. (2002) Galantamine—a novel cholinergic drug with a unique dual mode of action for the treatment of patients with Alzheimer s disease. CNS Drug Rev., 8, 159-176. 

---