Autonomic NS 6: Alpha stimulants (Vasopressors & Nasal Decongestants)

Question 1

defenition of Vasopressor

Answer 1

Increases pressure by Vasoconstriction (controling Peripheral resistance)

Question 2

enumerate vasopressors

Answer 2

• Noradrenaline
• Epherdrine
• Midodrine
• Phenylephrine

Question 3

mechanism of phenylepherine

Answer 3

Alpha 1 Agonist

Question 4

ADME (pharmacokinetics) of Phenylephrine

Answer 4

• Absorption: orally
• Distribution: pass BBB & into CNS (non catecholamine)
• Metabolism: Liver only (not MAO as it is no catecholamine)
• Excretion: renal

Question 5

Pharmacodynamics of Phenylephrine

Answer 5

Like Noradrenaline but weaker & longer duration

Question 6

Local use for Phenylephrine

Answer 6

1. Prolong action of local anesthetics
2. Nasal decongestant (irritant)
3. Mydratic drops for eye

Question 7

CVS use for Phenylephrine

Answer 7

Hypotension

Question 8

Phenylephrine for allergy

Answer 8

in common cold (with antihistaminics & paracetamol)

Question 9

side effect of Nasal decongestant

Answer 9

1. Rebound congestion
2. Atrophic rhinitis (atrophy of cilia & loss of smell)
3. Drowsiness in infants
4. Lipid pneumonia (if in oily solution)
5. Contraindicated with Hypertensive & Anginal Patients

Question 10

explain why rebound congestion occurs after using Nasal decongestants

Answer 10

• may cause irritation which further increase inflammation & congestion
• Causes tissue hypoxia, leading to reflex Vasodilatation & congestio

Question 11

Old group (systemic/oral) of Nasal decongestant

Answer 11

• Pseudoephedrine
• Phenylephrine

Question 12

New group (local) of Nasal decongestants

Answer 12

-Zoline family (Napha, tetrahydra, xylometa)
Never Trust Xylophones
* Naphazoline
* tetrahydrazoline
* xylometazoline

Question 13

why local group is better than systemic group of nasal decongestants

Answer 13

• Longer duration
• Less rebound congestion