3e Flashcards
(14 cards)
What are xanthines?
Normally occuring metabolites in the body
- IV Delivery
How are they chemically similar to methylxanthines (ex: Caffeine)?
Additional methyl group
What are some methylxanthine effects? (4)
- CNS Stimulation(*)
- Cardiac Stimulation
- Cerebral Vasoconstriction
- Skeletal muscle stimulation
What are relaxing/inhibitory effects of methylxanthines?
- Bronchodilation(*)
- Periphreal and coronary vasodilation
- Anti-Inflammatory Effects
What are the 2 suspected modes of action for methylxanthines?
- Inhibiting phosphodiesterase
- Blocking adenosine
Why are methylxanthines NOT used much?
- Low Therapeutic Index (TI)
- Ppl can metabolize them differently
- Other drugs do same thing better
Relating back to the last question, what plays a role in how one might metabolize these drugs?
- Age
- Organ function (Liver)
- Taking other drugs at same time.
What are side effects of methylxanthines?
- Nausea + Abdominal Pain
- Anxiety, vomiting, tremors
- Palpatations, arrythmias, seizures
What are methylxanthines used to treat (1st choice for it)?
Apnea of prematurity.
- Penetrates CSF stimulating resp centre
- Wider TI
What are 2 drugs that are methylxanthines?
- Theophylline
- Aminophylline
What is theophylline metabolized and eliminated by?
Metabolized –> Liver
Eliminated –> Kidneys
What are the Dosages and ranges for theophylline? (5, all in mcg/mL)
ZNNAS
No effect: 0-5mcg/mL
Therapeutic Range: 10-20mcg/mL
Nausea: 20-30mcg/mL
Arrhythmias: 30-40 mcg/mL
Seizures: 40+ mcg/mL
What does Aminophylline do?
Breaks down intotheophylline as primary agent.
- Can be more safely titrated
Where might aminophylline be used?
A Setting that can continuously deliver and monitor levels
- Ex: Pediatric ICU
