A medication is to infuse at 0.6 mg/hr. The solution available is 50 mg/150 mL. The nurse should set the IV pump to deliver how many mL/hr? (Round to the nearest whole number & fill in the blank with the numerical value only)

Calculation:

Given quantity = 0.04 g (grams)

Desired unit = mg (milligrams)

Convert from g to mg

1 g = 1000 mg

0.04 g × 1000 mg/g

= 40 mg

A. Second-generation antihistamines have shorter half-lives and require more frequent dosing compared to first-generation antihistamines: Second-generation antihistamines typically have longer half-lives, allowing once-daily dosing. They are designed for sustained action with improved compliance and fewer side effects.
B. First-generation antihistamines block both histamine and muscarinic receptors, while second-generation antihistamines primarily block histamine receptors: First-generation agents, such as diphenhydramine, cross the blood-brain barrier and exert anticholinergic effects by blocking muscarinic receptors. Second-generation antihistamines are more selective for peripheral H1 receptors, resulting in fewer CNS and anticholinergic side effects.
C. First-generation antihistamines are less likely to cause sedation compared to second-generation antihistamines: First-generation antihistamines are more likely to cause sedation because they easily penetrate the blood-brain barrier and affect central H1 receptors, unlike second-generation agents.
D. Second-generation antihistamines cross the blood-brain barrier, causing significant central nervous system effects: These medications are designed not to cross the blood-brain barrier significantly, which is why they are much less sedating and have minimal CNS effects compared to first-generation antihistamines.