L32 Drugs Modulating Mediators And Transmitters

Question 1

Give examples of non endocrine mediators

Answer 1

▪️Eicosanoids
▪️NO and O2 metabolites
▪️Monoamines( histamine and serotonin)
▪️Purines (ATP/ADP adenosine) 
▪️Peptides:constrictors and relaxants 
▪️Others: cytokines,growth factors..etc

Question 2

Why do we use drugs

Answer 2

▪️To suppress mediators or block their action if found in excess
▪️Increase mediators or mimic their action if found suppressed or malfunctioning

Question 3

How is synthesis of mediators blocked or suppressed

Answer 3

By inhibiting their synthesis

By blocking mediators’ receptors by receptor antagonists

Question 4

How can drugs inhibit synthesis in hypertension and bronchial asthma

Answer 4

1-using angiotensin converting enzyme inhibitors as ramipril to suppress angiotensin level to lower blood pressure when treating hypertension or manifestations of heart failure

2-using 5-lipoxygenase inhibitors as zileuton to suppress leukotriene formation during symptomatic treatment of bronchial asthma

Question 5

How can receptor antagonists block mediators’ receptors in severe vomiting and hypertension

Answer 5

▪️Using 5 hydroxy tryptamine (5-HT) antagonist as ondansetron to block selectively 5-HT3 centrally at the vomiting center and peripherally in the afferent nerve terminals in GIT to inhibit severe vomiting in chemotherapy
▪️using angiotensin 1 receptor blockers as valsartan to block effect of angiotensin and helps treatment of hypertension and heart failure

Question 6

How can drugs increase degradation during intesecticide toxicity

Answer 6

Using cholinesterase reactivators as oximes to reactivate the enzyme to become able to degrade excess accumulated Ach during insecticide toxicity

Question 7

How can drugs increase mediators or mimic their action if found suppressed

Answer 7

▪️By giving mediator itself
▪️Giving a drug that can mimic mediator action
▪️Stimulating mediator synthesis
▪️Increasing mediator release from stores
▪️Decreasing mediator breakdown
▪️Inhibiting uptake of mediator
▪️Activating mediators’ receptors

Question 8

Explain how giving mediator can increase action in cases of glaucoma

Answer 8

▪️Using prostaglandin analogue as latanoprost to reduce intra ocular pressure by enhancing aqueous humor drainage in cases of glaucoma

Question 9

How can giving a drug that can mimic mediator action help for treatment of angina pectoris

Answer 9

Using NO donners as organic nitrates in nitroglycerine which can cause veno and arterio-dilation that is demanded for treatment of angina pectoris and relieving symptoms of heart failure

Question 10

How can we stimulate mediator synthesis to treat hypertension

Answer 10

Using beta adrenoreceptors blocker nebivolol to activate nitric oxide synthase that will increase NO production lower the blood pressure when treating hypertension or manifestations of heart failure

Question 11

How can we increase mediator release from stores and used as flu remedy

Answer 11

Using dual acting sympathomimetics as pseudoephedrine that can release catecholamines indirectly from stores so used as nasal drops in flu remedy

Question 12

What is used in case of myasethina gravis to dec mediator breakdown

Answer 12

Use inhibitor of cholinesterase as reversible anticholinestrases,neostigmine that will increase ACH at motor end plate to inc skeletal muscles contraction

Question 13

How can inhibition of uptake of meditator be done in depression

Answer 13

Using selective serotonin uptake inhibitors as fluoxetine to increase 5HT within synaptic cleft that is needed to elevate mood and treat depression

Question 14

What can be used to activate mediator’s receptors to help prevent premature labor

Answer 14

Using a selective beta2 agonist as ritodorine to relax uterus to prevent premature labor