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Does SummaCare Cover Metformin?

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At a glance

  • Drug class / Oral biguanide, generic, prescription-only [1]
  • Labeled use / Type 2 diabetes: adults; children 10 and older for immediate-release tablets only [1][2]
  • Off-label uses / Prediabetes prevention, PCOS, weight loss [1]
  • Immediate-release maximum / 2,550 mg per day in divided doses for adults [1]
  • Extended-release maximum / 2,000 mg once daily for adults [2]
  • Renal cutoff / Contraindicated at eGFR below 30 mL/min/1.73 m2 [1]
  • SummaCare coverage details / Check your plan's drug list for the plan year

Checking SummaCare coverage

Tier placement, copays, quantity limits and prior-authorization rules for metformin are not reported on this page. They appear in your plan's current drug list and benefit details. Search for the exact product and strength on the prescription, such as immediate-release or extended-release tablets.

What metformin is labeled to treat

The immediate-release tablet label covers adults and children 10 and older with type 2 diabetes, as an adjunct to diet and exercise to improve glycemic control [1]. The extended-release tablet label covers adults only [2]. Prediabetes prevention, PCOS and weight loss are not labeled indications [1]. Metformin is also sold inside many combination products; this page refers to single-ingredient metformin [1].

Key label details

Adult immediate-release dosing starts at 500 mg twice daily or 850 mg once daily with meals and is titrated to a maximum of 2,550 mg per day in divided doses [1]. Extended-release starts at 500 mg once daily with the evening meal, up to 2,000 mg once daily, and the tablets are swallowed whole, never crushed, cut or chewed [2]. The label says to check eGFR before starting and at least yearly; metformin is contraindicated below 30 mL/min/1.73 m2, and starting is not recommended at 30 to 45 [1]. A boxed warning covers lactic acidosis, with risk factors that include renal impairment, age 65 or older, contrast studies, surgery and other procedures, hypoxic states, excessive alcohol intake and hepatic impairment [1]. The label also warns that vitamin B12 levels can fall, with subnormal levels in about 7% of patients in 29-week trials, and it directs measuring hematologic parameters annually and vitamin B12 every 2 to 3 years [1].

Immediate-release versus extended-release

Immediate-release and extended-release metformin have separate prescribing information [1][2]. When you look the drug up on the plan's drug list, use the product and strength written on the prescription. For information about metformin, see metformin.

Frequently asked questions

What is metformin approved to treat?
Type 2 diabetes. The immediate-release tablets are labeled as an adjunct to diet and exercise for adults and children 10 and older; the extended-release tablets are labeled for adults only [1][2]. Prediabetes, PCOS and weight loss are off-label uses [1].
Is metformin used for prediabetes?
Yes, off-label. In the Diabetes Prevention Program, metformin 850 mg twice daily reduced diabetes incidence by 31% over a mean 2.8 years versus placebo, while an intensive lifestyle program reduced it by 58% [3]. At 15 years the metformin reduction was 18% [4]. The labeled indication is still type 2 diabetes [1].
What is the maximum daily dose of metformin?
For adults on immediate-release tablets, 2,550 mg per day in divided doses [1]. For extended-release tablets, 2,000 mg once daily [2]. Children 10 and older on immediate-release tablets are capped at 2,000 mg per day [1].
What does the metformin label warn about?
A boxed warning for lactic acidosis, with risk factors including renal impairment, age 65 or older, contrast imaging, surgery, hypoxic states, excessive alcohol intake and hepatic impairment [1]. The label also warns that vitamin B12 levels can fall, with subnormal levels in about 7% of patients in 29-week trials, and directs periodic B12 measurement [1].
Where can I confirm whether my plan covers metformin?
In your SummaCare plan's current drug list and benefit details, which show tier, restrictions and your out-of-pocket cost. Look up the exact product and strength on the prescription, since immediate-release and extended-release metformin are separate labeled products [1][2].

References

  1. U.S. National Library of Medicine, DailyMed. Metformin hydrochloride tablets (Granules, immediate-release) prescribing information. Metformin hydrochloride tablets (Granules, immediate-release) label
  2. U.S. National Library of Medicine, DailyMed. Metformin hydrochloride extended-release tablets (Sun) prescribing information. Metformin hydrochloride extended-release tablets (Sun) label
  3. Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346(6):393-403. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin
  4. Diabetes Prevention Program Research Group. Long-term effects of lifestyle intervention or metformin on diabetes development and microvascular complications over 15-year follow-up: the Diabetes Prevention Program Outcomes Study. Lancet Diabetes Endocrinol. 2015;3(11):866-75. Long-term effects of lifestyle intervention or metformin on diabetes development and microvascular complications over 15-year follow-up: the Diabetes Prevention Program Outcomes Study
Evidence overview for Does SummaCare Cover Metformin?