Nadolol Dosage Availability
Yes, nadolol is available in a 20 mg tablet formulation, which is lower than 40 mg. 1
Available Tablet Strengths
According to the FDA drug label, nadolol tablets are manufactured and available in the following strengths for oral administration 1:
- 20 mg tablets
- 40 mg tablets
- 80 mg tablets
Clinical Dosing Context
While the 20 mg formulation exists, it's important to note that major cardiology guidelines typically recommend starting nadolol at 40 mg once daily for conditions like supraventricular tachycardia 2. The 2017 ACC/AHA hypertension guidelines also list nadolol with a usual dose range starting at 40-120 mg daily 2.
When Lower Doses May Be Appropriate
Lower doses (10-20 mg) have been studied and used in specific clinical scenarios 3, 4:
- Research has demonstrated that nadolol 10-20 mg daily can produce significant physiological effects, including dose-related intraocular pressure reductions 3
- A pilot study in mild asthma showed that 40 mg nadolol was well-tolerated when dose-escalated gradually 4
- Studies evaluating beta-adrenoceptor selectivity have examined nadolol at doses as low as 5 mg 5
Important Dosing Considerations
Dose adjustments are particularly critical in patients with renal impairment, as nadolol is renally eliminated 2. The guidelines specifically note that nadolol requires "reduced dosage with renal impairment" 2.
The availability of 20 mg tablets allows for flexible dosing in patients who may need lower initial doses due to renal dysfunction, elderly status, or concerns about tolerability, even though standard clinical practice typically begins at 40 mg 1.