What is the definition of a COUGH?
A voluntary OR involuntary RESPIRATORY tract REFLEX
What is the CLASSIFICATION and CAUSE of an ACUTE cough?
- LESS than 3 weeks
- Caused by: Viral URI or OTHER conditions (pulmonary emboli, pneumonia)
- Related to POST NASAL DRIP
What is the CLASSIFICATION and CAUSE of a SUBACUTE cough?
- 3-8 Weeks
- Caused by: Post infectious Cough, Bacterial Sinusitis
What is the CLASSIFICATION and CAUSE of a CHRONIC cough?
- 8 Weeks
- Most COMMON: Post Nasal Drip, Pulmonary Conditions (asthma), GERD
- ALSO: CHF, Medications (ACEI--20% due to inhibition of bradykinin break down, Non-selective Beta-blockers---due to bronchioconstriction)
What are the CAUSES of a CHRONIC cough in children?
- Foreign body ASPIRATION
- Esophageal MOTILITY Disorders
Why do ACE INHIBITORS cause a COUGH?
They STOP the breakdown of BRADYKININ
Why do Non-selective BETA-BLOCKERS cause a COUGH?
They cause BRONCHIOCONSTRICTION
What are the TWO TYPES of Coughs?
What is a PRODUCTIVE Cough?
- Wet or "CHESTY"
- CLEARS secretions from LRT
- Coughing up MUCUS
What is a NONPRODUCTIVE Cough?
- Dry or "HACKING"
- No PHYSIOLOGIC purpose
What are (6) COMMON Complications with a COUGH?
- Muscle Pain
- Excessive Sweating
- Urinary Incontinence
What are (4) LESS COMMON Complications with a COUGH?
- Heart Arrythmias
- Syncope--- passing out
- Stroke--- due to increased Intracranial Pressure
- Rib Fractures--- due to Osteoporosis
A TRIAD of symptoms that usually occur with the common COLD, FLU, & ALLERGY?
- Nasal Congestion
What is the MECHANISM of the COUGH REFLEX?
Irritants/Particulates----(Inflammatory Mediators)---- Sensory Nerve Stimulation---- CNS Cough Reflex Center= MEDULLA
What is the COUGH REFLEX Center?
What can TRIGGER (5) the COUGH REFLUX?
- Enviro Pollutants
- Job Exposures
- Mucosal [Ion]/osmolarity
The ____________________________ is the SENSORY nerve ENDINGS of respiraory epithelium.
AFFERENT Nerve Pathway
The Afferent Nerve Pathway contains receptors SENSITIVE to ___________________________ & __________________________.
- MECHANICAL Stress
- Specific CHEMICAL Transmitters
__________________________ are activates by ONE OR MORE mechanical stimuli.
Rapidly Acting Stretch Receptors (RAR)
What MECHANICAL Stimuli activate RARs?
- Lung Inflation
- Light Touch
- Physical changes---triggered by histamine from mast cells
________________________________ are activated DIRECTLY or SENSITIZED by a wide range of chemicals, but are realtively INSENSITIVE to mechanical stimuli.
Whats CHEMICALS activate Chemoreceptors?
- Substance P
- Neurokinin A
What FIBERS carry informations from CHEMORECEPTORS?
Bronchopulmonary C-fibers (Slow, thin unmyelinated nerve fibers)
Bronchopulmonary C-fibers RELEASE ________________________.
TACHYKININS------Substance P, Neurokinin A, Bradykinin
What FIBERS carry information from STRETCH & CHEMORECEPTORS?
Broncopulmonary A-delta fibers (Fast, thick myelinated nerve fibers)
Where to BOTH FIBERS (C & A-delta) JOIN to carry senssory Info to the CNS?
Afferent Branch of the VAGUS NERVE
Where do extensive SYNAPSES from the VAGUS occur?
The nulceus of the TRACTUS SOLITARIUS--associated with the Solitary Nucleus
Where is the Nucleus of the TRACTUS SOLITARIUS Located?
Upper MEDULLA OBLONGATA (each side)
What FUNCTIONS does the Nucleus of the TRACTUS SOLITARIUS play a role in?
- BP regulation
- Cough Reflex
- Gag Reflex
- Sneeze Reflex
What happens with the SUPPRESSION of the Medulla Oblongata?
- Increased Threshold to elicit Cough
- Decreased Cough Reflex
What is the COORDINATION of Nerve Impulses in the EFFERENT PATHWAY?
- CLOSE Epiglottis (following deep inspiration)
- SYNCHRONIZED Contraction (of diaphragm, intercostal and abdominal muscles)
- COUGH Rapidly (expel 2-3L of air)
What (4) MAJOR NERVES are involved in the EFFERENT Pathway of a COUGH?
- Vagus--coordinates muscles
- Glossopharngeal--closes epiglot, controls pharynx
- Phrenic--enervates diaphragm
- Trigeminal--afferent sensory fxn from scalp to chin
What are the PHARMACOLOGICAL Interventions of the CNS for a COUGH?
- Opiod Receptor Agonists--Codeine, Hydrocodone
- Antihistamines--diphenhydramine, chlorpheniramine, brompheniramine, promethazine
What are the PHARMACOLOGICAL Interventions used LOCALLY for a COUGH?
- Local anethetics
- Tachykinin receptor antagonists
EXCLUSIONS to Self-Care:
- Fever (if only symptoms are fever and cough)
- Unintended Weightloss
- Drenching PM Sweats
- Hx or Symp of underlying disease with Cough
- Foreign Object Aspiration
- Drug-associated (suspected)
- Cough > 7days
NON-PHARMACOLOGICAL Therapy for a COUGH?
- Cool Mist Humidifiers & Vaporizers
- Lozenges/Hard Candy
Avoid using COUGH & COLD medications in KIDS under the AGE ____________.
The 3 OPIOID Receptors TYPES?
- Mu, Kappa, Delta
- ---GPCRs w/ 7 transmembrane domains
Which RECEPTOR SUBTYPE for Opioids is associated with the MOST effects?
Mu--Analgesia, Sedation, Respiratory Depression, Decreased GI Motility
What are (8) IMPORTANT Opioid Receptor Agonists?
- Euphoria--dream-like sense of well-being
- Sedation & Drowsiness
- Respiratory Depression
The __________________ expresses HIGH LEVELS of _________ opioid receptors.
The Agonist activity of the _______ receptor ___________________ CHEMICAL and ELECTRICAL activity of the neurons.
- SUPPRESSES--- increases cough treshold & decreases cough reflex
Where is the Mu RECEPTOR located?
Membrane of NEURONAL CELLS
What type of SYSTEM does MORPHINE affect?
The Brain's PAIN & REWARD system
What provides a REWARD SENSATION or a feeling of RELIEF from TENSION when our basic needs are satisfied?
DOPAMINERGIC "pleasure-reward" Neural Tract
How does AGONIST ACTIVITY at Opioid Receptors contribute to ABUSE & ADDICTION?
They FLOOD the pleasure-reward system with ARTIFICIAL high levels of DOPAMINE
What is the difference between ABUSE & ADDICTION?
- Abuse: Self-Admin of drug in a disapproved manner with adverse consequences
- Addiction: Behavioral Pattern characterized by compulsive drug use
What are the OPIATES typically used as ANIT-TUSSIVES?
What is this DRUG and what is a DISTINCT characteristics?
- methylated hydroxyl
What is this DRUG and what are (2) DISTINCT characteristics?
What EFFECTS & USAGES does CODEINE have?
(Explain the REASON behind each USAGE)
- Antitussive: May involve DISTINCT receptors that bind codeine itself
- Analgesic: Codeines conversion to Morphine
- Pro-emetic: Causes N&V
How is Codeine METABOLIZED?
Demthylation at -OMe sites via CYP2D6 enzymes to MORPHINE
What DRUGS INTERACT with Codeine?
- CNS Depressants: additive adverse effects
- 2D6 Inhibitors: decrease metabolism of codeine to metabolism
Explain GENETIC POLYMORPHISM as it pertains to CODEINE?
- Good Metabolizers can convert codeine to morphine to have an analgesic effect.
- Poor Metabolizers cannot convert codeine to morphine but still have anttussive effect from codeine
What is the DOSING for CODEINE?
- Adult: 10-20mg Q4-6 hrs (Max 120mg daily)
- Not recommended for kids <2 [as a cough suppressent]
What are the ADVERSE EFFECTS of CODEINE?
What are the CONTRAINDICATIONS of CODEINE?
Known codeine or morphine HYPERSENSITIVITY
What are the PRECAUTIONS/WARNINGS of CODEINE?
- Impaired Respiratory Reserve
- Pre-existing Respiratory Depression
- Taking Sedative or Alcohol
What is considered an OVERDOSE for CODEINE?
- 0.5-1g in opioid naive patients
- ---respiratory depression & cardiopulmonary collapse
What is CODEINE's pregnancy category?
- C: Not near tern
- D: at high doses OR prolonged exposure
What is this DRUG and what is a DISTINCT Characteristic?
HYDROCODONE has _________x's the potency and efficacy of Codeine as an ___________________.
What additional PRODUCT can Hydrocodone be PAIRED WITH comapred to Codeine?
- Tussionex: Chlorpheniramine (8mg) & Hydrocodone (10mg) 5ml Q12h (10ml/24hrs)-- not recommended <6 yr
What is HYDROCODONE's pregnancy category?
- C: Not near term
- D: at high doses OR prolonged exposure
What is this DRUG and it's DISTINCT characteristics?
- SIMILIAR structure but NOT an OPIOID
- LACKS analgesic, respiratory depressant, abuse effects that opioids have
Why does DEXTROMETHORPHAN retain its ANTITUSSIVE effects?
- Activations of SIGMA receptors
- BLOCKS MAOI receptors
What can happen when taking HIGH doses of DEXTROMETHORPHAN?
(3 Step Process)
- Acute Euphoria, halluciantions
- Dysphoria & craving upon withdrawl
- Psychological dependence
What is the DOSING for DEXTROMETHORPHAN?
- 10-20mg Q4hr
- 30mg Q6-8hr
- 60mg Q12hr
- Max 120mg daily
What are the ADVERSE EFFECTS of Dextromethorphan at USUAL doses?
- Stomach Discomfort OR Constipation
What DRUGS interact with DEXTROMETHORPHAN?
- CNS depressants
- 2D6 Inhibitors
- Monoamine Oxidase Inhibitors (MAOI)
What 2D6 INHIBITORS canNOT be taken with Dextromethorphan and WHY?
- Paroxetine, Fluoxetine, Sertraline
- They inhibit serotonin re-uptake--dextro also inhibits re-uptake of dextro = LOTS of free serotonin ---- Increase risk of Serotonin Syndrome
Why CAN'T MAOIs be taken with Dextromethorphan?
- MAOIs decrease the metabolism of serotonin
- -----which leads to Serotonin Syndrome
What are the (7) MAIOs?
What are the (9) 2D6 Inhibitors?
What are the CONTRAINDICATIONS of Dextromethorphan?
- Must wait 14 days after MAIO is stopped to admin Dextro
- Known hypersensitivity
What is Dextromethorphan's PREGNACY category?
C: because there are no controlled human studies
What is the CENTRAL Mechanism of BENZONATATE?
Increases trigger threshold of MEDULLARY cough reflex
What is the PERIPHERAL Mechanism of BENZONATATE?
- ANESTHETIC action on peripheral nerve endings
- ---bind to INTRACELLULAR portion of voltage-gate Na+ channels
- ----------decrease rate of membrane depolarization
- ----------increase threshold for excitability
What is this DRUG and it's DISTINCT characteristics?
- Strutually similiar to other ester-type local ANESTHETICS (tetracaine)
The is the DOSING of BENZONATATE?
- Initial 100mg TID PRN
- As often as 100mg Q4hr PRN
- Max dose 600mg daily
- Not recommended <10yrs
What are the ADVERSE EFFECTS of Benzonatate?
What is the MAJOR counseling point of BENZONATATE?
DO NOT CHEW
How do Antihistamines affect CENTRAL Antitussive Mechanisms?
Depress Medullary Activity via blocking H1 receptors
How do Antihistamines affect PERIPHERAL Antitussive Mechanisms?
Have Local ANESTHETIC affects via blocking Na+ channels of peripheral nerves
What are FIRST GENERATION Anti-histamines?
- (Central and Peripheral effects)
Dosing, Adverse Effects, Drug Interactions & Pregnancy:
PROMETHAZINE & CODEINE
- Promethazine (6.25mg) & Codeine (10mg) 5ml Q4-6hr (max 30ml/24hr)
- Constipation, N/V, Sedation
- 2B6 & 2D6 Inhibitors
- Prometh:C Codeine: C/D
What are the 2B6 & 2D6 Inhibitors?
What is the DOSING for DIPHENHYDRAMINE for a Cough?
- 1/2 dose of cold/allergy
- Normally: 25mg Q4h (max 150mg daily)
- Pregnancy category: B
What are the reason to use CAMPHOR & MENTHOL to treat a cough?
- Counter irritant effects
- COLD abd MENTHOL sensitive receptor-1
What is the COUNTER-IRRITANT effect for Camphor & Menthol?
The distraction of the CNS for an irritant because of change in temperature
What are the TWO names for the clones menthol receptor?
- Cold & Menthol sensitive receptor-1
- Transient receptor potential channel M8
What TWO ways does the menthol receptor help relieve a cough?
- Senses COLD at peripheral nerve endings
- Menthol-induced Ca release from presynaptic Ca stores potentiates sensory synaptic transmission
What are Pro-tussives used for?
To help bring up mucus in a productive cough
What is GUAIFENESIN used as?
What is the MECHANISM of Gauifenesin?
- Increases VOLUME of secretions
- Reduces the VISCOSITY of secretions
What other FACTOR also increases the volume of respiratory secretions?
OSMOLARITY--- draws fluid out of respiratory tract into mucosal tissue
What is the DOSAGE of Gauifenesin?
- 200-400mg Q4 hr OR 1200mg BID
- Max daily 2400mg
What are the ADVERSE EFFECTS of Gauifenesin?
- N/V, stomach pain
- (Not common in normal dosage)
What are the DRUG INTERACTIONS of Gauifenesin?
What are the CONTRAINDICATIONS of Gauifenesin?
What is the PREGNANCY Category of Gauifenesin?
What will NOT break up mucus that is already formed?
What WILL break up mucus that is already formed and WHY?
- Mucolytics---lyzes disulfide bonds in mucuproteins presnet in mucus and decreases viscosity
- (facilitates removal of mucus/irritants by promoting productive cough)
WHEN should you refer a patient with a COUGH?
- Cough > 7days
- Cough worsens
- Development of other exclusions--fever
- Only symptoms cough and fever >101