Pharmacologic Therapy - Respiratory Disorders Flashcards
histamine
a major inflammatory mediator in ALLERGIC DISORDERS
often activated in these conditions:
- allergic rhinitis (hay fever, mold, dust)
- anaphylaxis
- angioedema
- drug fevers
- insect bites
- urticaria
what are ANTIHISTAMINES?
drugs that directly compete with HISTAMINE for specific receptor sites
- also known as HISTAMINE ANTAGONISTS
what are the properties of antihistamines?
- antihistaminic
- anticholinergic
- sedative
what are our TWO types of HISTAMINE RECEPTORS?
- H1 (histamine 1)
work mainly by conducting SM contraction & dilation of capillaries - H2 (histamine 2)
works mainly in the GI system; accelerates HR + secretes gastric acid
H1 antagonists
- work by blocking our H1 receptors
- mainly known as our “antihistamines”
- has primarily ANTICHOLINERGIC EFFECTS
examples:
chlorpheniramine, fexofenadine (Allegra), loratadine (Claritin), cetirizine (Zyrtec), diphenhydramine (Benadryl)
H2 blockers
- blocks our H2 receptors
- mainly used for acid-control / helps to REDUCE gastric acid in PUD
examples:
cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid)
MOA of antihistamines
- work by blocking and competing with HISTAMINE at the receptor sites
- **does NOT PUSH HISTAMINE OUT; simply just competes
- prevents adverse effects of histamine stimulations
- works much better if used earlier in histamine-mediated reactions
what are some ADVERSE REACTIONS when histamine is stimulated?
- think of severe allergic reactions!
- capillary permeability increases = increased BP/itchiness
- increased gastric secretions/secretions everywhere (saliva, lacrimal, bronchial etc…)
- increased HR
- SM constriction (difficulty breathing/blood flow/flushing)
**antihistamines work by REVERSING these effects
- decreases cap permeability by dilation
- decreases HR
- drying effects; decreases secretions
- sedative effect
antihistamine indications
- nasal allergies
- seasonal/perennial allergic rhinitis
- allergic reactions
- motion sickness
- parkinson’s dz
- sleep disorders
- common cold symptoms
**antihistamines do NOT CURE/KILL causative organism (curative), they just RELIEVE (palliative) symptoms
antihistamine contraindications
- drug allergy
- narrow-angle glaucoma
- cardiac disease/HT
- kidney disease
- asthma/COPD (do not use as SOLE DRUG THERAPY during acute asthma attacks **use epipen/albuterol)
- PUD
- seizure disorders
- BPH
- pregnancy
antihistamines adverse effects
drying effects **most common - ANTICHOLINERGIC EFFECTS
- dry mouth
- diff. urination
- constipation
- vision changes
- drowsiness (mild to deep sleep)
describe the difference between NON-SEDATING ANTIHISTAMINES vs. SEDATING HISTAMINES
NON-SEDATING HISTAMINES:
- developed to remove common side effect of sedation
- works more PERIPHERALLY, meaning they DO NOT cross the BBB/fewer CNS effects
- longer duration of action *can be taken once a day/has increased compliance rates
SEDATING-HISTAMINES:
- more older/original drugs
- works both CENTRALLY & PERIPHERALLY to block histamine; they cause sedation; however are often more effective in results
what are our NON-SEDATING ANTIHISTAMINES?
- fexofenadine (Allegra)
- loratadine (Claritin)
- cetirizine (Zyrtec)
loratadine
- taken typically once a day (tab/syrup form + taken in combo with decongestant - PSEUDOEPHEDRINE)
- relieves seasonal allergic rhinitis/itching
- pregnancy category B drug
what medications/drugs should NOT be given with LORATADINE?
- aclidinium
- azelastine
- ipratropium
- orphenadrine
- potassium chloride
- tiotropium
- umeclidinium
what are our traditional/SEDATING HISTAMINES?
- diphenhydramine
- brompheniramine
- chlorpheniramine
- dimenhydrinate
- meclizine
- promethazine
diphenhydramine
- avab. ORAL/PARENT/TOPICAL
- sedating/traditional
- also used as a hypnotic due to sedating effects
- XX older adults - creates a “hangover effect”
- used to relieve allergies, motion sickness, parkinsons, promote sleep
[*also used with epinephrine to manage anaphylaxis in ACUTE dystonic reactions] - pregnancy cat. B
what are the THREE MAIN TYPES of decongestants?
- ADRENERGIC
is the largest group; aka sympathomimetics - ANTICHOLINERGIC
less common; aka parasypatholytic - CORTICOSTEROIDS
are topical; intranasal steroids
MOA decongestants
- shrinks engorged nasal MM
- relieves nasal stuffiness
ADRENERGIC DRUGS - work by constricting small arterioles in the URI/nasal sinuses
NASAL STEROIDS - reduce inflammatory response by the organisms/creates an anti-inflammatory effect
decongestants indication
- nasal congestion / acute or chronic rhinitis / sinusitis / hay fever
- reduces swelling of the nares
contraindications decongestants *adrenergic drugs
- drug allergies
ADRENERGIC DRUGS: - narrow-angle glaucoma
- uncontrolled cardio dz
- HT
- DM
- hyperthyroidism
decongestants adverse effects
- nervousness
- insomnia
- palpitations
- tremors
- mucosal irritation/dryness (intranasal steroids)
- systemic effects (high doses);
headaches, HT, nervousness, dizziness, palpations
interactions decongestants
- adrenergic drugs + systemic sympathomimetic drugs = drug toxicity
- MAOIS > can increase BP when given with sympathomimetic nasal drugs
describe the different ROUTES of the decongestants
ORAL ROUTE
- prolonged effects, delayed onset
- less potent
- no rebound congestion
- mainly seen for adrenergic drugs
TOPICAL ROUTE
- prompt/rapid
- potent
- can cause rebound congestion/exacerbation risk
- topical adrenergic
INHALED INTRANASAL STEROIDS/ANTICHOL
- prophylactic usage for URI patients/symptoms
- X rebound congestion
what are some typical OTC decongestants?
- Nasacort AQ (triamcinolone acetonide)
- Flonase Allergy Relief (fluticasone propionate)
- Rhinocort Allergy Spray (budesonide).
*caution with nasal mucosal infections - can depress immunity
*drug allergies
oxymetazoline / afrin
- sympathomimetic/adren. drug
- similar structure to TETRAHYDROZOLINE
- dilates arterioles to constrict > reduces BF and congestion
- should not be used more than 3 days at a time (risk of REBOUND CONGESTION)
antitussives
- stops cough reflex
- used ONLY FOR NONPRODUCTIVE COUGHS
- have opioid or non-opioid
benzonatate
- type of antitussive drug; is NOT a OPIOID
- suppresses cough by NUMBING the STRETCH RECEPTORS in the RESP. TRACT
- numbness prevents STIMULATION of the COUGH REFLEX in the MEDULLA
- pregnancy C drug
benzonatate contraindications
- no known contraindications
- cautious with usage with patients with PRODUCTIVE COUGH
(antitussives also have opioids for usage - assess for opioid dependency/resp. depression
benzonatate adverse effects
- dizziness
- headaches
- sedation
- nausea
tuberculosis
medical diagnosis for any infection caused by the bacteria known as Mycobacterium tuberculosis
- causes GRANULOMAS in the lungs and accumulations of inflammatory cells
what are our FIRST-LINE ANTITUBERCULAR DRUGS?
- INH/ISONIAZID*
- RIFAPENTINE
- ETHAMBUTOL
- RIFABUTIN
- PYRAZINAMIDE (PZA)
- RIFAMPIN*
- STEPTOMYCIN
what are our SECOND-LINE DRUGS?
- BEDAQUILINE*
- CAPREOMYCIN
- CYCLOSERINE
- LEVOFLOXACIN
- ETHIONAMIDS
- OFLOXACIN
- KANAMYCIN
- PARA-AMINOSALICYLIC ACID (PAS)
what are the THREE GROUPS of TB DRUGS?
- protein wall synthesis inhibitors (PWSI)
- cell wall synthesis inhibitors (CWSI)
- other MOA (OMOA)
TB drugs depend on what for effectiveness
- have to consider TYPE of TB
- dosing
- duration of treatment/adherence (at least 6 months for TB treatment)
- type of drug combo
problems for TB therapy
- drug-resistance (MDR-TB)
- drug toxicity
- patient non-adherence
bedaquiline (sirturo)
- first drug approved to treat MDR-TB
- works by inhibiting mycobacterial ATP SYNTHASE
- ADVERSE EFFECTS: headaches, chest pain, nausea, QT PROLONGATION (BBW)
- interactions: ALCOHOL, MIFEPRISTONE, drugs with risk of QT PROLONGATION
- administer with FOOD
[new drug for MDR-TB; PRETOMANID]
isoniazid/INH
- the DRUG OF CHOICE for TB
- metabolized in the liver via ACETYLATION; not everyone has the gene for this metabolism–causing a “slow acetylator”–have to adjust dosing
- can be solo or used in combo
- ADV EFFECTS: LIVER DZ, PERIPHERAL NEURO, HEPATOTOXICITY/PYRIDOXINE DEFICIENCY
- may need to take vitamin supplements
rifampin / rifabutin / rifapentine
- used to treat infections by NON-TB MYCOBACTERIAL SPECIES
- ADV EFFECTS: SECRETIONS (URINE, FECES, SALIVA,SKIN, SWEAT > RED-ORANGE-BROWN COLOR and HEPATITIS
- oral
TB therapy patient ed
- remember–TB is spread via AIRBORNE DROPLETS: via human, animal etc../coughing or sneezing
- therapy can last 6 - 12 months
- very important to have strict adherence
- can be CONTAGIOUS during the initial period of illness
- no alcohol
