23. Pharmacology Of Eicosanoids. Drugs Acting On Smooth Muscle

Front 1

Name some leukotriene antagonists

Back 1

Zafirlukast, montelukast

Front 2

What are the indications for leukotriene antagonists

Back 2

Bronchial asthma

Front 3

What is the pathomechanism behind aspirin asthma?

Back 3

NSAIDs inhibit COX. When COX is inhibited all the arachidonic acid molecules that are produced will be converted into leukotrienes. Leukotrienes cause swelling, increased mucus secretion and bronchoconstriction in the bronchi, causing asthma.

Front 4

Name some prostanoid analogues

Back 4

Alprostadil, misoprostol, dinoprostone, epoprostenol, carboprost, latanaprost

Front 5

What are the indications for prostanoid analogues?

Back 5

Termination of pregnancy, induction of labour, prevention of peptic ulcers, maintaining ductus arteriosus, erectile dysfunction, postpartum haemorrhage, pulmonary hypertension

Front 6

Explain the mechanism of how prostanoid analogues can cause termination of pregnancy or induction of labour.

Back 6

Prostaglandin E1 and E2 analogues induce contraction of the uterus, thereby causing termination of pregnancy or induction of labour, depending on the concentration used.

Front 7

Explain the mechanism of how prostanoid analogues can stop post partum bleeding.

Back 7

Prostaglandin F2α analogues like carboprost induce contraction of the uterus and induce lysis of the corpus luteum, thereby stopping post partum bleeding. Normally, contraction of the uterus during labour compresses the blood vessels and thereby prevents haemorrhage. A lack of uterine contraction, called uterine atony, is the most common cause of post partum haemorrhage and can be treated with carboprost.

Front 8

Explain the mechanism of how prostanoid analogues can prevent peptic ulcers.

Back 8

Prostaglandin E1 analogues like misoprostol acts on EP3 receptors in the stomach and inhibits HCl secretion and induces gastric mucus secretion, thereby preventing ulcer development.

Front 9

Explain the mechanism of how prostanoid analogues can maintain the ductus arteriosus, and in which cases this is necessary.

Back 9

Prostaglandin E1 is important in maintaining the ductus arteriosus in infants. Alprostadil keeps the ductus arteriosus open, which is beneficial for congenital heart defects that need surgery when the ductus arteriosus is necessary for the survival before the surgery, so-called ductus-dependent congenital heart lesions.

Front 10

Explain the mechanism of how prostanoid analogues can treat erectile dysfunction.

Back 10

Alprostadil relaxes vascular smooth muscle in the corpus cavernosum when injected into it, thereby inducing erection.

Front 11

What is the mechanism of action of glucocorticoids which has to do with the eicosanoids?

Back 11

Glucocorticoids increase the synthesis of lipocortin, a protein which inhibits phospholipase A2.

Front 12

What is the mechanism of action of NSAIDs?

Back 12

NSAIDs inhibit COX-1 and/or COX-2, depending on the type of NSAID.

Front 13

Name some spasmolytics

Back 13

Metamizole, butylscopolamine, bencyclane.

No clinical use: papaverin

Front 14

What are the indications of spasmolytics?

Back 14

To treat spasms, often those that occur due to bile or kidney stones.

Front 15

What is the mechanism of action of papaverin?

Back 15

Papaverin is a PDE3 and PDE4 inhibitor, thereby increasing the level of cGMP, which causes smooth muscle relaxation.

Front 16

Name some drugs which contract smooth muscle

Back 16

Oxytocin, prostanoid analogues, ergot alkaloids

Front 17

What are the indications for oxytocin?

Back 17

Induce labour, postpartum haemorrhage, promote lactation

Front 18

What are the indications for ergot alkaloids?

Back 18

Induce abortion, postpartum haemorrhage

Front 19

Name some drugs which can be used as tocolytics (can cause the uterus to relax)

Back 19

β2 adrenergic agonists (Terbutaline, Salbutamol/albuterol)

Calcium channel blockers (Nifedipine)

Oxytocin receptor antagonists (Atosiban)

NSAIDs (Indomethacin)