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Flashcards in Final Review Deck (112):
1

Diabetic agents that cause pancreatitis?

Exenatide - GLP-1 (incretin) analog

Sitaglipitin - DPP-IV inhibitor (inhibits incretin break down)

2

Diabetic agents that liver function needs to be monitored?

TZDs (Pioglitazone and Rosiglitazone) - increase insulin sensitivity [Pioglitazone has a good lipid profile, both also cause fluid retention]

Acarbose - a-glucosidase inhibitor

3

Metformin?

Inhibits gluconeogenic enzymes via AMPK -- weight loss os common

AE - B12 def, lactic acidosis, possible disulfiram rxn (in the sense that alcohol causes hypoglycemia and metformin decrease glucose production)

4

Sulfonylurea?

Binds SUR1 subunit and blocks ATP-sensitive K+ channels

1st gen - Chlorpropamide -- watch for SIADH and DISULFIRAM rxn

2nd gen - Glyburide, Glipizide, Glimepiride

5

Canagliflozin

SGLT2 inhibitor

AE - infections and osmotic imbalance

6

Pegvisomant?

Growth hormone antagonist

7

Octreotide?

Somatostatin analog - inhibits release of GH, TSH, glucagon, Insulin and gastrin

45x more potent in inhibiting GH release compared to somatostatin

2x more potent in reducing insulin secretion

t1/2 = 80 minutes

Octreotide acetate - long acting suspension given at 4 week intervals

Clinical application - reduce hormone-secretion tumor symptoms, localize neuroendocrine tumors, acute control of bleeding from esophageal varices

AE - nausea, vomiting, abdominal cramps, flatulence, steatorrhea, constipation, biliary sludge, gallstones, sinus bradycardia, vit B12 def (with long term use), pain at injection site (common)

8

GnRH antagonists?

Ganirelix and Cetrorelix

9

Desmopressin and Vasopressin?

ADH analogs -- MINIMAL V1 affinity (SM cells on efferent)

Clinical application...
1. DOC for diabetes insupidus
2. Esophageal bleeding and colonic diverticular bleeding (vasopressin)
3. Coagulopathy tx in hemophilia A and vWF disease (Desmopressin)

AE - headache, nausea, abdominal cramps, allergic reaction

10

Glucocorticoid agonists and antagonists?

Agonist...
Hydrocortisone (Cortisol) [equal amt of anti-inflammatory and salt-retaining activity]
Prednisone
Methylprednisolone
Triamcinolone (aerosol) [no salt retaining ability]
Dexamethasone [no salt retaining ability]
Beclamethosone (aerosol)

Antagonist.... Mifepristone

11

Mineralocorticoid agonists and antagonists?

Agonists... Aldosterone and Fludrocortisone

Antagonists... Spirnolactone (watch out for hyperkalemia)

12

Tx of cerebral edema and Hodgkins Lymphoma?

Cerebral edema = dexamethasone

Hodgkin's lymphoma = prednisone

13

Aminoglutethimide?

Desmolase inhibitor - used to block all adrenal cortex hormones (ex. adrenal cancer)

14

Ketoconazole in tx of cushings and prostate cancer?

Non-selective inhibitor - inhibits desmolase, 17 hydrox and 17,20 lyase

15

Metyrapone?

11B hydroxylase inhibitor -- tx PREGNANT women with cushings

AE... salt and water retention, hirsutism, transient dizziness, GI disturbances

16

B blockers used in the treatment of hyperthyroidism?

Propranolol, Nadolol, Esmolol (short acting)

MOA - competitive block of B receptors inhibiting conversion of T4 to T3

With pts with asthma, can be given calcium channels instead (diltiazem and verapamil) as alternatives.

17

Oral Diatrizoate and IV iohexol?

iodinated radiocontrat media that suppress the conversion of T4 to T3 (5-deiodinase) in the peripheral tissue, kidney and liver. It is useful in rapidly reducing the T3 concentration in thyrotoxicosis.

18

Perchlorate, thiocyanate, pertechnetate?

Rarely used antithyroid drugs that inhibit iodide concentration in the gland by blocking the transportation of iodine in to the thyroid gland.
Possible development of APLASTIC ANEMIA.

19

Drugs that may provoke autoimmune/destructive inflammatory thyroiditis which can induce hypothyroidism?

1. amiodaron
2. INF-a and IL-2
3. Lithium - inhibits release of hormones and thyroid enlarge (hypothyroidism)
4. imatinib, sunitnib (TKRI-tyrosine kinase receptor decrease)
5. aminoglutethimide, sulfonylurea

20

Prostaglandins used for cervical ripening; uterine contractions; postpartum hemorrhage?

Cervical ripening and contraction = misoprostol (PGE1), Dinoprostone (PGE2)

Postpartum hemorrhage = misoprostol and Carboprost Tromethamine (PGF2 analog give IM administration)

21

Methylergonovine?

-partial a-agonist and some serotonin receptor activity
-tx postpartum hemorrhage
-ergot alkaloid [says erg in the name..]
-contraindicated if pt has CV or cardiac issues

22

Tocolytics?

Magnesium sulfate - uncouples excitation-contraction in myometrium inhibiting AP - may cause resp depression or cardiac arrest in mom or baby

Indomethacin - NSAID - may cause oligohydramnios and close PDA early

Nifedipine - Calcium channel blocker - safer than other tocolytics

Atosiban - oxytocin competitive antagonists - not approved in the US

B2 adrenoceptor agonist - phosphorylation of SmMKLCK inhibiting its interaction with calcium-calmodulin complex -- black box warning in the US as it may cause maternal death

23

Fibroblast growth factor-23?

Produced by osteoblasts and osteoclasts. FGF-23 inhibits calcitriol (activated vit D) production decreasing calcium and phosphate reabsorption in the kidneys and intestines.

*PTH stimulates calcitriol (1a-hydroxylase) activity in kidney whereas FGF-23 inhibits it

24

Teriparatide?

PTH analog
-low levels cause bone anabolism
-high levels cause bone catabolism

AE - hypercalcemia, hypercalciuria, osteosarcoma

25

Doxercalciferol?

1a-hydroxyvitamin D2

26

Paricalcitol?

19-nor-1,25 - dihydroxyvitamin D2

27

Calcipotriol?

vit D derivative used to treat psoriasis

28

Bisphosphonates (Alendronate)?

Suppresses activity of osteoclasts and inhibits bone resorption. It inhibits osteoclastic activity via decreasing farnesyl pyrophosphate synthesis by disrupting mevalonate pathway decreasing osteoclast H+ ATPase.

Uses - osteoporosis and Paget's disease

AE - adhynamic bone, esophageal irritation (risk reduced by drinking water and remaining in upright position for 30 minutes after taking medication), osteonecrosis of jaw

Ex. Risedronate, Ibandronate, Pamidronate, Zoledronate -- all very similar to aledronate

29

Denosumab?

Monoclonal antibody that binds RANKL (rank ligand). Binding to the RANKL leads to inhibition of osteoclastic activity.

Uses - osteoporosis

Subcutaneous every 6 months

AE - increase risk of infections

30

Cinacalcet?

Calcimemtic that stimulates the calcium-sensing receptors (CaSR) in parathyroid to circulating Calcium leading to decrease in PTH. When the receptors is activated by cinaclcet or free ionized calcium, it activates a signaling pathway to suppress PTH synthesis and release.

Uses - hyperparathyroidism

Oral admin

AE - nausea, vomiting, hypocalcemia, adynamic bone

31

Calcium gluconate?

-tx of hypocalcemic tetany
-Counteracts magnesium sulfate overdose used in eclampsia tx

32

Plicamycin (Mithracin)?

This is a cytotoxic anticancer drug used in cancer-related hypercalcemia.

AE - thrombocytopenia, hepatic and renal toxicity

33

Sevelamer?

Hyperphosphatemia occurs due to renal failure, PTH or vitamin D issue.

Sevalamer treats hyperphosphatemia by decreasing dietary absorption of phosphate by binding phosphate in the GI tract.

34

Sinemet?

Dopa prep containing Carbidopa AND Levodopa.

35

AE Levodopa?

1. wearing-off reactions - end of dose akinesia which can be related to the timing of levodopa so take more frequently at smaller doses
2. The on-off phenomenom - fluctuations in response that are unrelated to the timing of doses, mechanism is unknown and for pts with severe off-periods may take SC apomorphine
3. Vit B6 is required for dopa decarboxylase reaction so do not give with B6 b/c it increases peripheral metabolism of levodopa?
4. do not coadminister with MAOI as it may precipitate a hypertensive crisis
5. Do not give to psychotic patients b/c it may exacerbate the mental disturabance
6. contraindicated in angle-closure glaucoma
7. may lead to possible arrhythmias

36

Ergot dopamine receptor agonists?

Bromocroptine (at D2)

AE - pulmonary infiltrates, pleural and retroperitoneal fibrosis, erythromelalgia

37

Non-ergot dopamine receptor agonists?

Pramipexole and Ropinirole (transdermal patch)
*may cause increased somnolence

38

Apomorphine?

Nonergot dopamine agonist used for rescue therapy for tx of "off" episodes of akinesia in pts on dopaminergic therapy. It also has emetogenic properties so should be pretreated with the antiemetic, trimtheobenzamide.

AE - QT prolongation, dyskinesias, drowsiness, sweating, hypotension

39

MAO and COMT inhibitors used to treat parkinsons?

MAO B inhibitors - Selegitine (metabolite is methamphetamine which may lead to insomnia) and Rasagiline

COMT - tolcapone [may lead to fulminating hepatic necrosis!!] and entacapone

40

MAOI?

Isocarboxazid
Phenelzine
Tranylcypromine
Selegiline (MAO B at normal levels, MAO A at high levels)

-serotonin syndrome
-cheese reaction
-possible hypertensive crisis

41

SSRI?

Citalopram
Escitalopram
Fluoxetine
Fluvoxamine
Paroxetine
Sertraline

-block SERT

AE-sexual dysfunction, SIADH, GI distress

42

TCAs?

Amitriptyline
Clomipramine
Desipramine
Imipramine
Nortriptyline

-block SERT and NET
-block a, H, M, Na as well leading to tons of side effects

43

SNRIs?

Venlafaxine
Duloxetine

AE - hypertension

44

SARI?

Trazadone ("bone") ad Nefazodone

5HT reuptake antagonist

Nefazodone - associated wit hepatotoxicity

Trazodone - blocks a1 and h1 receptors, extreme sedation, good hypnotic, but there is a troublesome side-effect of priapism

45

Mirtazapine?

Noradrenergic and specific serotonergic antidepressant (NASSA)

Antagonist of central presynaptic a2 receptors and antagonist of 5-HT2 and 5-HT3 receptors. Little H1 antagonism.

Sedation, weight gain, dry mouth

46

Buproprion?

NDRI
*helps with smoking cessation

AE - seizures

47

Classical antipsychotics?

1. Chlorpromazine (low potency) - may lead to ventricular arrhythmias, corneal deposits
2. Fluphenazine (high potency)
3. Haloperidol (high potency)
4. Thioridazine (low potency) - retinal deposits

48

Atypical antipsychotics?

1. clozapine -prototype [D1, D2, D4, 5HT2, a, M blockers - may cause seizures, agranulocytosis and weight gain] -- safest with pregnancy with a risk of hyperglycemia
2. risperidone - [DOC!!!! - blocks 5HT2 way more than D2]
3. olanzapine
4. quetiapine
5. ziprasidone
6. aripiprazole - partial agonist at D2 and 5HT1A as well as antagonist at 5HT2A receptors
7. paliperidone - 9-hydroxyrisperidone [active metabolite of risperidone]

**more of an effect on weight gain

49

AE of antipsychotics?

4 hrs - Dystonia (muscle spasms)= tx with anti-muscarinics

4 days - Akathisia (rigidity) = tx with propranolol and clozepam

4 weeks - Parkinsonism (bradykinesia) = tx with antimuscarinics

4 months - Tardive Diskynesia = tx with clozapine and diazepam

50

Neuroleptic malignant syndrome?

FEVER
F-fever
E- encephalopathy
V-vital instability
E-elevated enzymes
R - rigidity

**tx with dantrolene or bromocriptine

51

Busiprone?

-5HT1 agonist
-2nd line agent for GAD
-2 week onset
-really good profile
-anxiolytic effect

52

Why should alprazolam not be used in panic disorder tx?

Rebound anxiety b/t doses and withdrawal

53

Performance anxiety tx?

B blockers with high lipophilicity [propranolol and nadolol]

54

Tx PTSD?

acute - Sertraline and Paroxitine [SSRIs]

chronic - Sertraline [SSRI]

55

Benzodiazepines?

-BZ1, BZ2 binding on GABAa increasing frequency of channel opening

-Diazepam, Lorazepam, Triazolam, Temazepam, Oxazepam, Midazolam, Chlordiazepoxide, Alprazolam

LOT - does not go through phase I reaction

AE - CNS depression, ataxia, dependence, drowsiness, confusion

56

Flumazenil?

Benzo receptor antagonist -- rapid onset reversal but may precipitate withdrawal in dependent pts

57

Barbiturates?

-bind GABA channels and increase duration of opening
-glutamate and sodium channel blocks as well

Phenobarbital, pentobarbital, thiopental, secobarbital

AE - CNS, CV and respiratory depression [exacerbated by alcohol as alcohol also binds GABA receptors so increases potentiation], dependence, hangover effect, decrease ain tolerance

58

Non-benzo benzodiazepine receptor agonist?

1. zolpidem - sleep initiation
2. zaleplon - tx insomnia
3. eszopiclone - longest half life of 6 hrs and maintains sleep

**act at BZ1 subtype of benzodiazepine receptors acting as hypnotics with minimal muscle relaxing/anticonvulsant activity, lack of tolerance and low AE incidence

59

Ramelteon?

Melatonin receptor agonist - MT1 and MT2 melatonin receptors indicated for tx of insomnia

*short half life and used for people who have problems of sleep onset

60

Hydroxyzine?

Antihistamine with antiemetic activity that is also approved for symptomatic relief of anxiety.

61

Gabapentin and pregabalin?

Block presynaptic VG Ca2+ channels preventing release of glutamate - seizure tx

AE - sedation and ataxia

62

Levetiracetam?

binds synaptic vesicle glycoprotein 2A (SV2A) - may affect release of glutamate and GABA - very unclear as to what it does other than binding to protein in the vesicle membrane

**low AE profile

63

Ethosuximide?

DOC of absent seizures (3Hz)

EFGHIJ
Ethosuximide
Fatigue
GI disturbance
Headache
Itching
steven Johnson syndrome

64

Valproate?

Sodium channel inactivator preventing AP transmission.

AE - weight gain, GI disturbance, tremor, pancreatitis, hepatotoxicity, neural tube defects if taken during pregnancy

65

Tx of status epilepticus?

1. IV lorazepam
2. if seizure continues - IV phenytoin or Fosphenytoin (soluble with better bioavailability)
3. if seizure continues - IV phenobarbital
4. if seizure continues - general anesthesia with IV midazolam, propofol or barbiturates

66

Phenytoin?

Sodium channel inactivator

AE - diplopia, ataxia, GINGIVAL HYPERPLASIA, HIRSUTISM, stevens johnson syndrome, lupus like syndrome

ZERO order kinetics

67

Lamotrigine?

Sodium channel blocker

STEVENS JOHNSON SYNDROME

68

Topiramate?

Sodium channel blocker and GABA activator

AE - weight loss, fatigue, kidney stones

69

Vigabatrin?

prevents GABA metabolism

AE - irreversible visual field loss

70

Tiagabine?

prevents GABA reuptake

71

Felbamate?

Blocks NMDA channels and potentiates GABA

**used for refractory epilepsy

AE - aplastic anemia, hepatotoxicity

72

antimuscarinic poisoning antidote?

Physostigmine

73

Stimulant overdose tx?

Ammonium chloride

74

B blocker poisoning antidote?

Glucagon

75

CCB poisoning antidote?

IV calcium with glucagon and NE

76

TCA poisoning antidote?

sodium bicarb with NE

77

MAOI-serotonin antidote?

Cyproheptadine

78

Methanol and Ethylene glycol toxicity antidote?

Fomepizole or ethanol [alcohol dehydrogenase inhibitor]

79

Cyanide toxicity antidote?

nitrite+nitrate+thiosulfate [methylene blue required for methemeglobin production]

OR

hydroxocobalamin

80

Lead poisoning tx?

EDTA
dimercaprol
succimer
unithiol
diazepam
dexamethasone
mannitol

81

Arsenic poisoning tx?

Acute tx - dimercaprol and unithiol

Chronic tx - succimer

gas poisoning - mannitol (osmotic diuresis), bicarb, dimercaprol within 24 hrs then unithiol and succimer after 24 hrs

82

Mercury toxicity tx?

acute - dimercaprol, unithiol or succimer

chronic - unithiol and succimer

83

Iron toxicity tx?

Deferoxamine

84

Mestranol?

Prodrug that is converted to ethinyl estradiol - used in contraceptives

85

Clomiphene?

ER antagonists at the hypothalamus that inhibits the negative feedback leading to increased LH and FSH production -- stimulates ovulation

AE - ovarian hyper-stimulation leading to enlargement of ovary, multiparity, hot flashes, nausea, vomiting, breast tenderness, weight gain

86

Fulvestrant?

ER antagonists everywhere in the body -- treats hormone-responsive breast cancer that is resistant to the other first-line anti-estrogen therapies

87

Letrozole?

Similar to anastrozole which is an aromatase inhibitor decrease the synthesis of estrogen

AE - hot flashes, musculoskeletal disorders, reduced bone mineral density, joint symptoms

88

Exemestane?

Irreversible aromatase inhibitor

89

Degarelix?

GnRH antagonist used to treat advanced prostate cancer

90

Danazol?

partial agonist at androgen receptors - weak CYP450 inhibitor

AE - acne, hirsutism, weight gain, menstrual disturbances, hepatic dysfunction

91

Mifepristone?

Competitive inhibitor at progesterone receptor - helps stop pregnancy with misoprostol leading to abortions

AE - GI disturbances, vaginal bleeding, atypical infection

92

Finasteride?

5a-reductase inhibitor preventing conversion of testosterone to DHT

Tx - BPH and hair loss

AE - impotence, gynecomastia

93

Flutamide?

Competitive inhibitor of androgen receptors

Tx - advanced prostate cancer

AE - gynecomastia, hot flashes, impotence, hepatotoxicity

94

What is the MOA of oral contraceptives?

1. prevent ovulation - suppress LH and FSH release by preventing estrogen fluctuations by providing pt with stable estrogen level

2. impair implantation - by maintaining elevated progesterone level by providing pt with stable elevated progestin

95

Compare progestins and levels of androgen activity?

Highest androgen activity = levonorgestrel [post-coital and implants] and noregestrel [progestin only pill]

Lower androgen activity = norethindrone [progestin only pill]

Even lower activity = desogestrel and noregestimate

Antiandrogenic = Drospirenone

96

What are the benefits of combined oral contraceptives?

• Reduction on the risk of endometrial cancer
• Reduction in the risk of ovarian cancer
• Improved regulation of menstruation
• Relief of benign breast disease
•Prevention of ovarian cysts
• Reduction in the risk of symptomatic pelvic inflammatorydisease
• Improvement in acne control

97

AE associated with oral contraceptives?

Nausea, bloating, breakthrough bleeding that improve spontaneously by 3rd cycle.

Breakthrough bleeding is more of a problem with lower doses of estrogen b/c estrogen stabilizes the endometrium.

Insulin resistance b/t progestins may cause insulin resistance by competing with insulin for its receptor. It is very rare that oral contraceptive swill lead to hyperglycemia.

Hirsuitism - due to androgenic progestins

Melasma - due to estrogen stimulation of melanocyte production

Amenorrhea

Dyslipidemia - low-dose have no impact on HDL, LDL, TAG or total cholesterol levels

CV disorders - increased risk of thromboembolism, thrombiphlembitis, HTN, MI, cerebral and coronary thrombosis esp in women with other risk factors - this is due to estrogen causing increased production of factor VII, factor X , and fibrinogen

Carcinogenic - possible increase in risk of cancer (NOT for endometrial and ovarian though! - oral contraceptives decrease the incidence of these cancers)

Depression - requires cessation of therapy

98

What are the progestin-only pills?

These are not widely used, but contain NORETHINDRONE or NOREGESTREL. They are slightly less effective compared to the combined pills. There is no risk of thromboembolic evens due to lack of estrogen which is really what stimulates the increased risk of thrombosis.

MOA - effectiveness lies within thickening cervical mucus and altering endometrial surface to impair sperm implantation

99

Methylxanthines?

Caffeine, theophylline, Theobromine -- caffeine is the most widely consumed stimulant -- these substances block presynaptic adenosine receptors. Normally the adenosine receptors inhibit NE release, so blocking the receptors potentiates the NE release therefore acting as a stimulant. Adenosine is also a natural promoter of drowsiness, so by blocking adenosine receptor there is a potential of insomnia.

CNS actions...
100-200mg caffeine - decrease fatigue and increase mental alertness
1.5g caffeine - produces anxiety and tremors
2-5g of caffein - spinal cord stimulation

Tolerance can rapidly develop and withdrawal leads to fatigue and sedation.

100

Nicotine withdrawal?

mild - pt is irritable, sleepy, relapse is common

Nicotine addiction tx..
1. nicotine replacement therapy - transdermal patch, gym, nasal spray, etc
2. sustained-release bupropion
3. Varenicline - partial agonist at nicotinic receptors in CNS

101

How do you tx opioid withdrawal?

1. Replace with long-acting opioid then slowly reduce dose -- methadone and buprenorphine are the most commonly used
2. Detox with adrenergic agonists - Clonidine and Lofexidine [both are a2 agonist] that prevent the rebound firing of the adrenergic neurons that occur with the withdrawal symptoms
3. Naltrexone - opioid antagonist with high affinity to mu opioid receptors that do not satisfy craving but rather relieve withdrawal symptoms

102

How do you treat alcohol addiction?

1. Disulfiram - aldehyde dehydrogenase inhibitor - creates aversion to drinking

2. Naltrexone - orally available opioid antagonist -reduces alcoholic craving

3. Acamprosate - NMDA receptor antagonist - prevents relapse

4. Topiramate - facilitates GABA function and antagonizes glutamate receptors - this may reduce cravings, but is not FDA-approved for this indication

103

Tx benzo withdrawal?

Diazepam and chlordiazepoxide - long half-life benzos b/c they prevent rebound withdrawal symptoms

In elderly and people with liver failure - it is better to administer intermediate-acting drugs, Lorazepam and Oxazepam - these go straight to phase II glucuridation so put less stress on the liver

104

Inhaled anesthetics?

• Gases -N2O [megaloblastic anemia]
• Volatile halogenated hydrocarbons
-Halothane [hepatotoxicity, heart depression]
-Enflurane [seizure potential, heart depression, most resp depression]
-Isoflurane [TPR depression, resp depression]
-Desflurane [TPR depression]
-Sevoflurane [TPR depression]
-Methoxyflurane [nephrotoxicity]


105

MAC vs potency vs oil:air partition coefficient vs induction?

low MAC - high potency - high oil:air coefficient - slow induction
[ex. Methoxyflurane]

high MAC - low potency - low oil:air coefficient - fast induction
[ex nitrous gas]

106

IV anesthetics?

• Barbiturates - thiopental [ultra-fast barb]
• Propofol - massive hypotension, GABAa potentiator
• Ketamine - NMDA blocker, bad dreams, dissociative anesthesia
• Etomidate - stable CVS, GABAa potentiator

Droperidol
Fentanyl

107

Local anesthetics?

short-acting = procaine [METABOLIZE TO PABA ANALOG so do not give with sulfonamides!], chloroprocaine

intermediate-acting = lidocaine, mepivacaine, prilocaine [converts hemoglobin to methemoglobin]

Long-acting = tetracaine, bupivacaine [CARDIOTOXIC], etidocaine, ropivacaine

Amide (2 i's -- liver excretion) vs ester (1 i -- esterase)

108

Non-depolarizing blockers?

Benzylisoquinolines - tubocurarine (prototype), atracurium, cistracurium, mivacurium

Ammonio steroids - pancuronium, rocuronium [alt to succinylcholine], vecuronium

Atracurium - metabolizes t o Laudanosine which leads to seizures and hypotension so Cistacurium was created to decrease the AE profile an dit also has decreased histamine release

**AE - hypotension from histamine release (B) and tachycardia from M2 block (A)

109

Depolarizing blockers?

Succinylcholine -- two ACh molecules linked end-to-end

AE - bradycardia (musc agonist), histamine release, muscle pain, HYPERKALEMIA, increase intraocular and intragastric pressure

Do not give it....
• History of malignant hyperthermia
• History of skeletal muscle myopathies.
• Major burns.
• Multiple trauma
• Denervation of skeletal muscle
• Upper motor neuron injury.

110

Drugs for chronic spasms that act in CNS?

1. Diazepam - facilitates GABAa receptor activation increasing frequency of Cl- channel opening
2. Baclofen - GABA agonist at GABAb receptors [CNS receptor that is a G-protein coupled receptor that is also inhibitory so when you activate it, you relax the skeletal muscle]
3. Tizanidine - a2 agonist in CNS

111

Drugs for chronic spasms that act on skeletal muscle?

1. Dantrolene - interferes with release of Ca2+ by binding to the ryanodine receptor in the SR of skeletal muscle -- also used in malignant hyperthermia
2. botulinum toxin

112

Drugs for acute spasms?

-prototype = cyclobenzaprine -- similar in structure to TCA which strong antimuscarinic side effects
-there are centrally acting drugs functioning at the brainstem that create relief of acute muscle spasm caused by local trauma or strain