Fosamax Appetite & Cravings Changes: What the Clinical Evidence Actually Shows

Does alendronate directly change appetite or cravings?

Alendronate acts on bone. It binds to bone hydroxyapatite and inhibits osteoclast activity, and it is not metabolized [1]. The Fosamax label does not describe an appetite, craving or food-reward effect, and its osteoporosis adverse-reaction tables do not list appetite loss or cravings among reactions reported at 1% or more [1].

The label and trials report upper-GI effects rather than hunger ratings or craving measures.

What did the fracture trials actually measure?

The Fracture Intervention Trial (FIT) enrolled 2,027 postmenopausal women with existing vertebral fractures and followed them for 36 months [2]. The alendronate dose started at 5 mg daily and increased to 10 mg daily after 24 months [2]. New morphometric vertebral fractures occurred in 8.0% of the alendronate group versus 15.0% of the placebo group, relative risk 0.53 [2].

FIT reported no significant difference between groups in numbers of adverse experiences, including upper-GI disorders [2]. A Cochrane review of 11 trials including 12,068 women also found no statistically significant difference in adverse events in any included study [3]. These are fracture and adverse-event analyses, not appetite endpoints.

Which labeled GI effects could be mistaken for appetite change?

The Fosamax label lists abdominal pain, acid regurgitation, constipation, diarrhea, dyspepsia, musculoskeletal pain and nausea as adverse reactions occurring in 3% or more of patients [1]. In the two 3-year US/multinational trials, drug-related abdominal pain was 6.6% with alendronate 10 mg daily (n=196) versus 4.8% with placebo (n=397). Nausea was 3.6% versus 4.0%, dyspepsia 3.6% versus 3.5%, and esophageal ulcer 1.5% versus 0% [1].

The label also warns about esophagitis, esophageal ulcers and erosions, occasionally with bleeding and rarely followed by stricture or perforation [1]. It instructs patients to discontinue Fosamax and seek medical attention if dysphagia, odynophagia, retrosternal pain, or new or worsening heartburn develops [1]. Nausea or pain when swallowing may make eating less appealing, but these symptoms do not show whether alendronate changes appetite or cravings.

Does the 30-minute wait or food interaction affect appetite?

The label instructs patients to take alendronate at least one-half hour before the first food, beverage or medication of the day, with plain water only, and not to lie down for at least 30 minutes and until after the first food [1]. The label says that not following these instructions may increase the risk of esophageal adverse experiences [1].

Food also affects absorption. Coffee or orange juice taken with alendronate reduced bioavailability by about 60%, and bioavailability was negligible when alendronate was taken with or up to 2 hours after a standardized breakfast [1]. Dosing 30 or 60 minutes before breakfast reduced bioavailability by about 40% compared with dosing 2 hours before eating, yet alendronate was effective in trials when taken at least 30 minutes before breakfast [1]. None of these findings addresses appetite or cravings.

What about taste changes?

Taste perversion was reported in 0.5% of patients taking alendronate 10 mg daily and 1.0% taking placebo in the US/multinational studies; in FIT the figures were 0.1% and 0.0% [1]. The rates were low and similar between the two groups [1].

Who should use caution because of upper-GI problems?

The label says to use caution in patients with active upper gastrointestinal problems such as Barrett's esophagus, dysphagia, other esophageal diseases, gastritis, duodenitis, or ulcers [1]. Esophageal abnormalities that delay emptying, such as stricture or achalasia, and inability to stand or sit upright for at least 30 minutes are contraindications [1].