Ferrous Sulfate for Cough Management
Ferrous sulfate can be effective in treating specific types of cough, particularly ACE inhibitor-induced cough, but is not recommended as a first-line treatment for general cough management.
Effectiveness in ACE Inhibitor-Induced Cough
- Ferrous sulfate has demonstrated efficacy in attenuating cough associated with ACE inhibitor therapy in randomized, double-blind, placebo-controlled trials 1
- For patients who cannot discontinue ACE inhibitor therapy, ferrous sulfate (256 mg daily) is recommended as one of several pharmacologic options to suppress cough 1
- Iron supplementation has shown a 45% reduction in mean cough score in patients with ACE inhibitor-induced cough 1
- The mechanism appears to be related to iron's inhibition of nitric oxide synthase, which decreases nitric oxide generation in bronchial epithelial cells 2, 3
Treatment Algorithm for ACE Inhibitor-Induced Cough
- First-line approach: Discontinue the ACE inhibitor - this is the only uniformly effective treatment 1, 4
- Second-line approach: Switch to an angiotensin receptor blocker (ARB) - ARBs do not affect bradykinin metabolism and typically do not cause cough 4, 5
- Alternative pharmacologic options (if ACE inhibitor cannot be discontinued):
Effectiveness in Other Types of Cough
- In women with unexplained chronic cough unresponsive to targeted treatments, iron supplementation may be beneficial if iron deficiency is present 6
- A study of 22 non-smoking women with chronic unexplained cough and iron deficiency showed significant improvement in cough symptoms after iron supplementation (330-660 mg ferrous sulfate daily for 2 months) 6
- Case reports suggest that treating iron deficiency anemia may resolve drug-resistant chronic cough in some patients 7
Important Considerations and Cautions
- Iron supplementation should only be considered after appropriate evaluation for common causes of cough 8
- Ferrous sulfate tablets themselves can cause severe endobronchial inflammation if aspirated, particularly in elderly patients with decreased gag reflexes 9
- For general cough management not related to ACE inhibitors or iron deficiency, ferrous sulfate is not recommended 1
- Monitoring for side effects of iron supplementation (gastrointestinal symptoms, constipation) is necessary 2
Dosing Recommendations
- For ACE inhibitor-induced cough: 256 mg ferrous sulfate daily 1, 2
- For cough associated with iron deficiency: 330-660 mg ferrous sulfate daily 6
- Treatment duration of 1-2 months may be required to see full benefit 6, 2
Monitoring Response
- Assess cough severity before and after treatment using a cough scale or diary 2
- Consider measuring serum ferritin levels before initiating therapy to confirm iron deficiency in cases of unexplained chronic cough 6
- If no improvement is seen after 4 weeks of therapy, consider alternative treatments 1, 6