Jeffrey Kindler, chairman and CEO of Pfizer (NYSE:PFE), is getting plenty of unsolicited advice from analysts and self-proclaimed financial experts. They say Pfizer must make a big, bold buy to reverse course on its skidding stock and to blast it out of its revenue doldrums.

Here's my advice: Don't do it.

Yes, there are valuable strategic acquisitions and even large-scale collaborations. But a big acquisition won't necessarily solve Pfizer's goal of finding new drugs with long-patent lives aimed at "high-potential" disease areas -- Alzheimer's disease, schizophrenia, diabetes, pain, cancer, and inflammation.

Many supposed target companies own assets that aren't even in the same ZIP code as those disease-treatment categories. And some targets have big drugs that face patent expirations of their own in the next few years, as well as legal matters that could provide distractions.

Clearly, Pfizer has to do something
For the past five years, Pfizer's stock price has lagged both the S&P 500 and the Amex Pharmaceutical Index of mostly Big Pharma stocks. However, Pfizer has outperformed both indices in the past six months.

But the biggest worry is that Pfizer must offset the pending U.S. patent expiration of Lipitor, which accounted for 26% of revenue during the first nine months of 2008. Generics will begin hitting the U.S. market in late 2011.

With $26 billion in cash, cash equivalents, and short-term investments, Pfizer has some financial flexibility -- which gives the merger-and-acquisition speculators plenty of ammunition. However, if those speculators would consult Pfizer's own comments about strategy and R&D focus, they'd see that a big deal could produce a big disappointment.

I won't comment on every misplaced M&A idea, but here are a few I believe Pfizer should avoid.

Candidate No. 1
The sales pitch centers on Allergan (NYSE:AGN) as a recession-rebound play as women resume their desire for Botox, breast implants, and other forms of self-improvement that are elective and rarely insured.

However, Pfizer's strategy doesn't say anything about medical devices, cosmetic surgery, or dermatology, which accounted for a little more than half of Allergan's revenue for the nine months ended Sept. 30.

The one match is eye drugs, which, for the nine months ended Sept. 30, produced $1.54 billion in sales for Allergan -- or 47% of its product sales. Pfizer's glaucoma drugs Xalatan and Xalacom produced $1.29 billion for the same period.

Ophthalmology is one of Pfizer's top 10 research areas, rather than a "high potential" category. It is conducting phase 2 trials for one glaucoma drug and one for treating age-related macular degeneration. Pfizer also sells Macugen for wet age-related macular degeneration, but sales are modest.

Could Pfizer overcome antitrust questions in a bid for Allergan, which sells three glaucoma drugs and has two in mid-stage clinical trials? And even if it could, does Pfizer want to buy those other non-strategic assets?

Candidate No. 2
Bristol-Myers Squibb (NYSE:BMY) has several drugs for schizophrenia, rheumatoid arthritis, and cancer that would fit well with Pfizer's "high-potential" drug group.

Bristol also has a number of cancer drugs in development, as well as a key collaboration with Pfizer for apixaban, an experimental anticoagulant. The companies reported in August that one late-stage clinical trial, for preventing blood clots in veins of patients undergoing total knee replacement, failed to meet its goal. Other clinical trials continue.

However, Bristol has several major products facing patent expiration in a few years. Its best-seller, the anticoagulant Plavix, goes off patent in 2011. Plavix provided $4.1 billion, or 27% of revenue, for the first nine months of 2008.

The hypertension drug Avapro and its cousin Avalide contributed $974 million, but the Avapro patent expires in 2012. All three are licensed from Sanofi-Aventis (NYSE:SNY), which, a couple of years ago, appeared to be Bristol's most likely suitor.

A recent report by Morningstar says Bristol's commercial rights for the rapidly growing antipsychotic Abilify end in 2012, potentially allowing the drug's licensor, Japan's Otsuka Pharmaceutical, to seek "less favorable" terms from Bristol's point of view.

And Bristol recently lost its chance at control of the cancer drug Erbitux when it was outbid by Eli Lilly (NYSE:LLY) for control of ImClone Systems.

Candidate No. 3
Wyeth (NYSE:WYE) has several drugs that would be attractive, including the pneumococcal vaccine Prevnar and the multiuse anti-inflammatory drug Enbrel, which Wyeth sells outside the U.S. and Canada.

Wyeth is narrowing its R&D to focus on areas such as cancer and Alzheimer's disease, which match Pfizer's R&D goals. However, Wyeth carries some legal baggage, and many products don't fit Pfizer's strategy.

Wyeth appears to be in the final stages of settling all liability cases involving its diet drugs Redux and Pondimin. Wyeth still has $1.36 billion in a litigation reserve balance -- the company has set aside $21.1 billion over the years -- to deal with pending cases.

Wyeth is also defending approximately 8,700 lawsuits involving plaintiffs alleging that its hormone-replacement therapy drugs -- Premarin and Prempro -- caused cancer and/or heart disease. Wyeth has won most of the 30 breast-cancer cases that had been set for trial, and it hasn't yet set a reserve.

Pfizer would probably have to divest Wyeth's consumer-health business. (Pfizer sold a much bigger consumer-health operation to Johnson & Johnson (NYSE:JNJ) in late 2006.) Wyeth and Pfizer both have large animal health businesses, which could create antitrust issues.

Among major prescription drugs, the Effexor XR antidepressant, which will face generic competition in about two years, is Wyeth's biggest seller. The heartburn drug Protonix is already subject to generics.

Foolish final thoughts
CEO Kindler didn't dissuade speculation recently, when he was quoted in The Financial Times as saying, "We are open to opportunities and constantly looking at those which are big, small, and in-between."

He could go for the big score -- just as his predecessor, Hank McKinnell, did. But while each potential target has some good points, the overall picture -- the purchase price, the cost and time of integrating companies, the selling of assets, and so on -- makes a big buy a risky move for Pfizer.

For related Foolishness:

Johnson & Johnson and Pfizer are both recommendations of Income Investor, and Lilly is a former pick of that service. Pfizer is also a choice at Inside Value, and the Fool owns some shares.

Fool contributor Robert Steyer doesn't own shares of companies cited in this story. He suggests that Pfizer buy Philippine Long Distance Telephone and Fortune Brands, as well as Futura Medical, which trades on the London Stock Exchange, to create a company with the symbol PFE-PHI-FO-FUM. Philippine Long Distance is an Income Investor recommendation. The Motley Fool has a disclosure policy.