Salivary flow

Question 1

which receptors mediate salivary flow? Mechanism of salivary secretion

Answer 1

Parasympathetic: Cholinergic System @ M3 linked G protein

Mech: ACh binds G protein - M3 receptor –> phospholipase C generates InP3 –> releases Ca2+ from ER –> activates apical Cl- / basolateral K+ channels –> fluid/Cl- secretion

Sympathetic: norepinephrine –> increases protein secretion

Question 2

3 classes of Rx for Xerostomia?

Answer 2

1) parasympathomimetrics
2) Radio-protector
3) saliva substitutes

Question 3

Which classes of drugs induce xerostomia?

Answer 3

1) antihistamines (esp FIRST generation)
2) decongestants (ex pseudophedrine - vasoconstrictive)
3) Antidepressants (amitryptiline)
4) antipsychotics (Haloperidol)
5) AntiHTN (reserpine xVMAT, chlorothiazide, metropolol, CCBs)
6) ANTICHOLINERGICS (atropine, scopolamine)

**choose one w/ less anticholinergic effects!

Question 4

Medical causes of xerostomia?

Answer 4

endocrine disorders (DM, hypothyroid), infections (hep C), neuro disorders (parkinsons), genetic disorders (CF, Downs, celiac), Nutritional deficiencies, radiation to head/neck, Graft vs. host, Autoimmune (SJOGREN’s) – use DMARDs

Question 5

Xerostomia

Answer 5

• PERSISTENT dry mouth…
• difficulty swallowing/speaking, mucosal/gingival lesions, inc risk candidiasis/caries, etc
• taste alteration!
• inc fluid intake/weight gain

Question 6

Cevimeline and Pilocarpine

Answer 6

Muscarinic Agonists

Cevimeline: receptor selectivity M3»M1, Cyp3A4/2D6 metabolism
AEs: angina, bronchoconstriction, arrhythmias, MI,
Contraindications: asthma, cholelithiasis/nephrolithiasis, COPD, geriatric, pregnancy

Pilocarpine: no receptor selectivity
AEs/contraindications – same as cevimeline + PSYCHOSIS (inc CNS involvement)

Question 7

Amifostine

Answer 7

Free Radical Scavenger Orphan Drug

• • Cisplatin nephroprotective
• • head and neck radiation SALIVARY GLAND PROTECTIVE

Question 8

Scopolamine

Answer 8

Off label drug used for:

• • Sialorrhea (hypersalivation)
• • motion sickness (nausea/vomit prevention)
• • Pre-op dec salivation and bronchial secretion
• • reduction in parkinson’s spastic states
• • pupil dilation

Question 9

Glycopyrrolate

Answer 9

Anticholinergic used for Sialorrhea

Question 10

Recommendations for oral drug administration w/ dysphagia?

Answer 10

• take first thing in the morning before eating
• take w/ full glass of plain water
• sit upright 30+ minutes/stand
• do not chew/crush tablet

Question 11

Recommendations for pills that float/sink?

Answer 11

float:
swallow capsule and water w/ head bent forward

Sink:
use flexible plastic bottle, form seal with mouth and do not let air in as you swallow