Yes. While I do not know what cocaine measures vs the mg of concerta in the blood, this is definitely possible. For example, some aerosol sprays for sinus issues can lead to a positive amphetamine test.

Methylphenidate (component which makes up concerta) is the closest pharmaceutical equivalent to cocaine. Through research, studies have shown that cocaine addicts cannot distinguish between the two drugs when administered intravenously

Edit: Kassie: (first, I stand by my answer). I did not say meth, please re-read my answer. Depending on the test administered, false tests can occur. Please reference the following as in indicator of the possible similarties which exists with MANY drugs.

The following structurally related compounds produced positive results when tested at levels equal to or greater than the concentrations listed below.
Compound Concentration
(-)-Nicotine 350 ug/ml
The following compounds were found not to cross-react when tested
at concentrations up to 100 µg/ml.
Acetaminophen DL-Homatropine
Acetylsalicylic Acid Hydrocodone
Albumin Hydromorphone
Amitriptyline (+/-)-Isoproterenol
D-Amphetamine Lidocaine
Ampicillin Maprotiline
Aspartame Methadone
Aspirin Meperidine
Atropine Methadol
Benzocaine Methamphetamine
Benzoylecgonine Methapyrilene
(+)-Brompheniramine Methaqualone
Caffeine Methylphenidate
Chloroquine (+/-)3,4-MDMA
(+)-Chlorpheniramine Morphine
(+/-)-Chlorpheniramine Morphine-3-ß-d-glucuronide
Chlorprothixene (1S,2S)-(-)-N-Methyl-Ephedrine
Codeine Naloxone
Creatine Naltrexone
r-Cyclodextrin ß-Naphthaleneacetic acid
Cyclobenzaprine (+)-Naproxen
(-)-Deoxyephedrine Nortriptyline
Dextromethorphan Nicotinic Acid
4-Dimethylaminoantipyrine Oxalic Acid
5,5-Diphenylhydantoin Penicillin-G
Diazepam Pentobarbital
Dopamine Perphenazine
Doxylamine Pheniramine
Ecgonine Methyl Ester Phenobarbital
EDDP Phenothiazine
(-)-Ephedrine L-Phenylephrine
(+)-Ephedrine a-Phenylethylamine
(+/-)-Ephedrine Phentermine
(+/-)-Epinephrine (+/-)-Phenylpropanolamine
Erythromycin Primidone
Furosemide Procaine
Glucose Promethazine
Guaiacol Glyceryl Ether d-Propoxyphene
Hemoglobin Secobarbital
Sodium Chloride D(+)Trehalose
Tenocyclidine Trifluoperazine
.9-Tetrahydrocannabinol Tyramine
Theophylline Triprolidine Hydrochloride
Thioridazine Vitamin C
Trimethobenzamide

Edit 2: kassie: “So all these rumors are false, there are over the counter cold medications in methamphetamine, and those would never show up on a drug test it is the drugs that are in it that cause the meth to come up positive”

I do am not trying to be rude, but I have some concerns. First, “those drugs would never show up on a drug test”. I think you may be a little un-aware of how the procedure works. ALL synthesized products will show in a urine drug test; however, it is only those that are tested for that are indicated.
Second. “it is the drugs that are in it that cause the meth to come up positive” Im a little unsure (due to wording) what you mean here. When you say it is the drugs that are in it, are you talking about meth (since that is what you thought i said)? If that is the case, EVERYTHING in meth is a what causes a positive test, meaning, meth is the product which is compromised of ingredients, specifically, C10H15N.