TRENTON, N.J. (AP) — New tests designed to help doctors pick the right hepatitis C medicine for patients could mean faster cures and lower costs.

Quest Diagnostics Inc.’s latest two tests can predict whether two recently approved medicines — Zepatier and Daklinza –will fight a patient’s specific type of hepatitis C or whether the liver-destroying virus likely would “resist” them. Several months ago, Quest had launched other tests to help doctors decide if four older medicines would suit patients.

There are six hepatitis C “genotypes,” plus some subtypes, and now six approved medicines that each treat one or more of those types. The right choice of drug should mean the patient will be cured quickly and would avert wasting considerable money, as the new generation of hepatitis C drugs each cost tens of thousands of dollars for a course of treatment.

Patients are tested before treatment starts to determine which hepatitis genotype has infected them so their doctors can pick a drug approved for that type.

Now doctors can also have patients’ blood tested to determine if the virus has a mutation that would limit that drug’s effectiveness. If a virus has mutated during treatment, a patient would then need to switch to another medicine.

The tests cost about $700 to $750 each, but most insurers cover them and Quests offers some patients financial help. Which test or tests are run depends on which genotype the patient has, whether they’ve had prior treatment and how much damage the virus has caused.

Until recently, treating the hepatitis C virus required taking multiple daily pills and getting frequent injections, for up to a year. Barely half of patients were cured with those regimens, and flu-like and other side effects left many patients miserable or unable to complete their treatment.

But since late 2013, Gilead Science Inc., Merck & Co., Bristol-Myers Squibb Co. and AbbVie Inc. have launched drugs that are more tolerable and cure 90 percent or more of patients in eight to 12 weeks.

While doctors and patients have gravitated to the new drugs, many insurers are limiting the number of patients receiving them because of the staggering cost of treatment. The expense is also straining the budgets of government health programs. The most expensive and most widely used of the six drugs, Gilead’s Harvoni, for example, carries a list price of $94,000 per patient.

But the newest one, Merck’s Zepatier, approved in January, was launched with a list price about 40 percent below that.

Because of the increased competition, insurers now are demanding discounts of up to 45 percent off list prices to cover specific hepatitis C drugs.

Nearly 4 million Americans have chronic hepatitis C, a blood-borne virus often spread through injected drug use. Many don’t learn they’re infected until the “silent” virus has caused major damage to the liver.

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