What are the most common long-term side effects of thiazides, ACEIs, ARBs, and CCBs?

The short version: the evidence here is too thin to name "most common" with any confidence, and for several drug classes the retrieval comes up nearly empty. What follows is from the records that actually match.

For thiazide diuretics, the common long-term side effects in this retrieval are hyponatremia (low sodium) and hypomagnesemia (low magnesium). One cohort of 2,613 outpatient adults new to hypertension treatment found that about 30% of those exposed to a thiazide developed hyponatremia, with an adjusted rate 1.6 times higher than non-users [3]. A large population-based Rotterdam Study of nearly 10,000 adults found thiazides linked to lower serum magnesium in a dose- and duration-dependent way, with odds of hypomagnesemia roughly three times that of non-users [4]. Another meta-analysis of 18 observational studies found small rises in fasting blood glucose—about 5 mg/dL on average, more at higher doses [2]. Long-term thiazide use also lowered parathyroid hormone and osteocalcin in elderly adults, and reduced bioavailable testosterone in men [1]. Notably, the same meta-analysis that showed a modest glucose rise showed no significant increase in hemoglobin A1c [2], so diabetes conversion is not established from these records.

For ACE inhibitors, the evidence in this retrieval is sparse on common long-term side effects. The strongest signal is anemia. A review reports that captopril reduced hemoglobin, hematocrit, and red blood cell mass in 9 of 12 maintenance hemodialysis patients, with reversal after stopping the drug [5]. In congestive heart failure, ACE inhibitors normalize elevated erythropoietin, and this parallels clinical improvement [5]. A large Taiwanese cohort of 28,497 advanced CKD patients on ACEIs or ARBs found an elevated rate of hyperkalemia hospitalizations: 9.2 per 100 patient-years versus 6.7 in non-users [6]. This is a meaningful risk but not "most common" in the typical hypertension population.

For ARBs, the evidence is thinner still. One study of 501 acute ischemic stroke patients found ARBs reduced all-cause mortality but did not report common side effects [7]. The same CKD cohort above included ARBs and showed the hyperkalemia risk [6]. Beyond that, the retrieval offers nothing on typical ARB side effects like dizziness, fatigue, or angioedema (which is less common than with ACE inhibitors).

For calcium channel blockers, the retrieval is almost entirely about overdose, drug interactions, or narrow special populations. One case-control study suggested a modest association between CCBs and breast cancer (odds ratio 1.4, confidence interval 0.9–2.4), but the finding was not statistically significant [8]. A trial of CCBs plus beta-blockers for angina found dizziness caused withdrawals in 3.5–4.5% of patients on amlodipine [9]. That is a single-study figure from a narrow population.

The most important gap: this retrieval contains no long-term safety data for these drugs in the general hypertension population for the outcomes that matter most—heart failure, stroke, kidney failure, or death. The one synthesis paper found that calcium antagonists appeared less effective than diuretics and ACE inhibitors for preventing heart failure (20–30% difference), but that is a secondary analysis [10]. There is no head-to-head comparison of serious adverse events over years.

My call: The evidence here is too thin and too narrow to name "most common" long-term side effects for these drug classes in the general hypertension population. For thiazides, the most well-documented effects in these records are hyponatremia, hypomagnesemia, and a small glucose rise. For ACE inhibitors, anemia and hyperkalemia show up in specific populations. For ARBs and CCBs, the retrieval is essentially empty on common long-term side effects. Confidence: low