Pharmacotherapeutics Flashcards
What are the 4 categories of steroid potency
- Lowest
- Low
- Intermediate
- High
When would you use the lowest/low potency in the treatment of allergies
- Usually used on dermatological problems on the face
- Most often used for maintenance and can be long term
(Hydrocortisone, or triamcinolone (nasocort))
Contraindications of low potency steroids
hypersensitivity and does not penetrate mucous membranes well
When would you use an intermediate potency steroid
- Usually on the body and extremities
- Atopic dermatitis
- Severe dermatitis
- Usually short term
(triaminolone - low potency in nasal steroids)
Contraindications of intermediate potency steroids
hypersensitivity and pediatric patients
When would you use a high potency steroid
- Psoriasis
- Severe poison ivy
- severe atopic dermatitis
- Only suitable for short term
Contraindications of high potency steroids
hypersensitivity and pediatric patients.
MOA of topical steroids
Steroids play a role in interfering with mast cell degranulation that results in decreased histamine and capillary permeability. (Also blocks phospholipase A2 which blocks prostaglandins and leukotrienes)
Examples of oral/topical corticosteroids used to treat allergic disorders
- Asthma - steroid inhalers, oral if severe (prednisone)
- Allergic rhinitis - Topical (in nose)
- Oral steroids useful in reducing eosinophils, prostaglandins, and other WBC involved in immune response
- Topical steroids for atopic dermatitis
Topical steroid affect on HPA axis
When topical steroids are absorbed, they tell your HPA axis that it does not need to make as much cortisol. Over time the cortisol production is dampened enough that the HPA forgets to make more steroid (HPA axis suppression). Takes 9-12 months to fully restore.
What adverse skin effects are associated with topical steroids
- Dermatitis
- Hypopigmentation
- Skin atrophy - most common
- Striae
- Infections
What is the main use of second generation antihistamines
Allergic rhinitis (and urticaria)
How do antihistamines work
They block H1 receptor sites to prevent the histamine reactions. They also inhibit the wheal and flare response on the skin so they must be stopped prior to skin testing
1st generation antihistamines
Highly sedative, because the cross into the CNS. And interact with other receptors (not just H1)
2nd generation antihistamines
Very little sedative reaction (do not cross into CNS). They interact and are specific to H1 receptors.