Lecture 11- Over the Counter Drugs - Cough and Cold Flashcards
What are the 3 classes of drugs involved for cough and cold?
- Antit-tussives
- Decongestants
- Expectorants
Commonly avaible OTC cough and cold medication contain either singly or in combination of a ____, ____ , ____ and/or anti____ /____
decongestant; anti-tussive or cough suppressent; expectorant; antipyretic or analgesic
What is the most common symptom of upper respiratory tract viral infections?
cough
The cough reflex is initiated by the stimualtion of ____ nerves innervating the throat and lungs.
sensory
Which receptors do sensory neurons contain that detect irritants and inflammation?
P2X3 and TRPV1
Sensory neurons send coughing information to the ____ in the brainstem, medulla oblongata
Nucleus tractis solitarus (nTS)
Efferent neurons via ____ and ____ nerves stimulate the diaphragm, intercostal muscles and lungs to initate a cough.
parasympathetic; motor
OTC drugs that inhibit the cough reflex do so mostly by inhibiting neurons in the ____.
nTS.
____ is a mu opioid receptor agonist.
Opioid
mu opioid receptors are located in the ____ as well as peripheral nerves innervating the respiratory tract.
nTS
Are opioid receptors inhibitory/excitatory G-protein coupled receptors?
inhibitory (Gi - GPCR)
Gi-coupled GPCRs inhibit ____ activity and reduce neuronal activity.
Adenylate cyclase (AC)
Activation of opioid receptors inhibit ____ channels, and activate ____ channels and inhibit ____ (AC).
calcium; K+; adenylate cyclase
What is the effect on the brain from the inhibition of AC, adenylate cyclase?
reduced neuronal activity and reduced transmitter release.
Opioid receptors are also located in the brainstem regions that mediate breathing reflex, in the ____ complex in the medulla oblongata.
Prebotzinger
High dose opioids can inhibit the ____ reflex and lead to death.
breathing
Codeine is a ____ agonist; it is not very potenet but has high risks.
partial
____ is a centrally active NMDA receptor antagonist.
Dextromethorphan
What is the effect od dextromethorphan on the brain?
inhibits neurons in the nTS
NMDA receptor is a ____ ion channel gated by ____ (excitatory), which leads to neuronal activation.
ligand-gated; glutamate.
Dextromethorphan blocks the activation of the ____ receptor and leads to the inhibition of neuronal activation.
NMDA.
____ is an antihistamine (H1 inverse agonist)
Diphenhydramine
H1 receptors are G____ coupled receptors located on respiratory smooth muscles, stimulate sensory nerves producing coughing.
Gq
Diphenhydramine is an inverse agonist meaning it acts as an ____ in the presense of an ____ which is ____.
antagonist; agonist; histamine.
Diphenhydramine crosses the ____ to suppress neurons in the ____.
Blood-brain barrier; nTS.
What is one of the most effective non-prescription treatment of cough that is not found at the pharmacy?
Honey
What are the 3 drugs disccused in the Anti-tussives section?
- Codeine
- Dextromethorphan
- Diphenhydramine
Nasal congestion is due to swelling (____) of the nasal mucosa and edema caused by ____.
edema; vasodilation
Does the sympathetic or parasympathetic nervous system control the vasuclar tone?
sympathetic.
____ adrenergic receptors are located on vascular arterioles and activation leads to vasoconstriction.
alpha 1
____ adrenergic receptors are located on vascular arterioles and veins, and well as broadly throughout the central and peripheral nervous system.
alpha 2
____ adrenergic receptors are located on bronchioles (smooth muscle relaxation) and in the heart (increased cardiac output)
Beta
Alpha 1 adrenergic receptors are G____ coupled receptors; they convert PIP2 into ____ and ____.
Gq; IP3 and DAG
Alpha 2 adrenergic receptors are G____ coupled receptors. They are responsible for the inhibition of adenylate cyclase (AC).
Gi
Beta adrenergic receptors are G____ coupled receptors.
Gs.
For alpha 1, activation of G____ proteins increase PLC and IP3 pathways. This stimulates release of ____ and smooth muscle ____.
Gq; calcium; contraction.
For alpha 2, inhibition of adenylate cyclase reduces ____ which is an inhibitor of myosin light chain kinase, and enzyme that phosphorylates myosin and causes ____. Inhibition of ____ increases MLCK activation and increases smooth muscle ____.
cAMP; contraction; cAMP; contraction.
What are sympathomimetic drugs?
drugs that produce effects similar to activation of the sympathetic nervous system.
What is the predominent neurotransmitter present in the sympathetic nervous system?
Noradrenaline or norepinephrine.
____ is a non-specific agonist at the alpha and beta adrenergic receptors; it is a sympathomimetic drug.
Pseudoephedrine.
Pseudoephedrine activates alpha adrenergic receptors in mucosa of the respitaory tract leading to ____ of blood vessels, reducing edema and swelling and opens up nasal passages.
vasoconstriction
Pseudoephedrine activity at the beta adrenergic receptors causes ____ ____ ____ leading to dilation of the bronchi and increased mucociliary clearnce helps clear the nasal passage.
smooth muscle relaxation.
What are the other effects of Pseudoephedrine?
- shrinks swollen nasal mucous membranes
- reduces tissue hypermia
- reduces edema and nasal congestion
- increases nasal airway latency
Pseudoephedrine is structurally related to ____ and has stimulant properties.
Amphetamine
____ is a specific alpha 1 adrenergic receptor agonist.
Phenylephrine
Phenylephrine leads to vasoconstriction in the nasal mucosa but does not lead to ____ ____ ____ in the bronchi nor does it impact the heart rate.
smooth muscle relaxation
____ cannot be chemically transformed into methamphetamine as the structures are different but pseudoephedrine can be transformed.
Phenylephrine
____ is an alpha 2 adrenergic agonist.
oxymetazoline.
What is the risk with prolonged use of oxymetazoline?
- Can lead to more congestion than it was before; Rhinitis Medicamentosa or rebound congestion.
Alpha ____ are restrcited to vascular structures but alpha ____ is not.
1;2
Which G-protein coupled receptor is susceptible to rebound signaling?
Gi
What are the 3 drugs discussed in the section of Decongestants?
- Pseudoephedrine
- Phenylephrine
- Oxymetazoline
What is the one drug disscused for expectorants?
Guaifenisin also known as mucinex
Guaifenesin increases the output of bronchial secretions by by decreasing the ____ and ____ (facilitates expulsion via the cough relfex, makes it less sticky.
adhesiveness and surface tension
